Language Evolution and Computation Bibliography

Grammatical agreement is present in many of the world's languages today and has become an essential feature that guides linguistic processing. When two words in a sentence are said to "agree", this means that they share certain features such as "gender", "number", "person" or others. The primary hypothesis of this paper is that marking agreement within one linguistic phrase reduces processing effort as phrasal constituents can more easily be recognized. The drive to reduce processing effort introduces the rise of agreement marking in a population of multiple agents by means of an incrementally aligned mapping between the most discriminatory features of a particular linguistic unit and their associative markers. A series of experiments compare feature selection methods for one-to-one agreement mappings, and show how an agreement system can be bootstrapped.

Communication is a key capability of autonomous agents in a multi- agent system to exchange information about their environment. It requires a naming convention that typically involves a set of prede- fined names for all objects in the environment, which the agents share and understand. However, when the agents are heteroge- neous, highly distributed, and situated in an unknown environment, it is very unrealistic to assume that all the objects can be foreseen in advance, and therefore their names cannot be defined beforehand. In such a case, each individual agent needs to be able to introduce new names for the objects it encounters and align them with the naming convention used by the other agents. A language game is a prospective mechanism for the agents to learn and align the naming conventions between them. In this paper we extend the language game model by proposing novel strategies for selecting topics, i.e. attracting agent’s attention to different objects during the learning process. Using a simulated multi-agent system we evaluate the pro- cess of name alignment in the case of the least restrictive type of language game, the naming game without feedback. Utilising pro- posed strategies we study the dynamic character of formation of coherent naming conventions and compare it with the behaviour of commonly used random selection strategy. The experimental results demonstrate that the new strategies improve the overall con- vergence of the alignment process, limit agent’s overall demand on memory, and scale with the increasing number of the interacting agents.

This paper compares two prominent approaches in artificial language evolution: Iterated Learning and Social Coordination. More specifically, the paper contrasts experiments in both approaches on how populations of artificial agents can autonomously develop a grammatical case marking system for indicating event structure (i.e. `who does what to whom'). The comparison demonstrates that only the Social Coordination approach leads to a shared communication system in a multi-agent population. The paper concludes with an analysis and discussion of the results, and argues that Iterated Learning in its current form cannot explain the emergence of more complex natural language-like phenomena.

Languages vary widely but not without limit. The central goal of linguistics is to describe the diversity of human languages and explain the constraints on that diversity. Generative linguists following Chomsky have claimed that linguistic diversity must be constrained by innate parameters that are set as a child learns a language. In contrast, other linguists following Greenberg have claimed that there are statistical tendencies for co-occurrence of traits reflecting universal systems biases, rather than absolute constraints or parametric variation. Here we use computational phylogenetic methods to address the nature of constraints on linguistic diversity in an evolutionary framework. First, contrary to the generative account of parameter setting, we show that the evolution of only a few word-order features of languages are strongly correlated. Second, contrary to the Greenbergian generalizations, we show that most observed functional dependencies between traits are lineage-specific rather than universal tendencies. These findings support the view that-at least with respect to word order-cultural evolution is the primary factor that determines linguistic structure, with the current state of a linguistic system shaping and constraining future states.

Human genetic and phenotypic diversity declines with distance from Africa, as predicted by a serial founder effect in which successive population bottlenecks during range expansion progressively reduce diversity, underpinning support for an African origin of modern humans. Recent work suggests that a similar founder effect may operate on human culture and language. Here I show that the number of phonemes used in a global sample of 504 languages is also clinal and fits a serial founder-effect model of expansion from an inferred origin in Africa. This result, which is not explained by more recent demographic history, local language diversity, or statistical non-independence within language families, points to parallel mechanisms shaping genetic and linguistic diversity and supports an African origin of modern human languages.

In coming to understand the world—in learning concepts, acquiring language, and grasping causal relations—our minds make inferences that appear to go far beyond the data available. How do we do it? This review describes recent approaches to reverse-engineering human learning and cognitive development and, in parallel, engineering more humanlike machine learning systems. Computational models that perform probabilistic inference over hierarchies of flexibly structured representations can address some of the deepest questions about the nature and origins of human thought: How does abstract knowledge guide learning and reasoning from sparse data? What forms does our knowledge take, across different domains and tasks? And how is that abstract knowledge itself acquired?

We constructed a corpus of digitized texts containing about 4\% of all books ever printed. Analysis of this corpus enables us to investigate cultural trends quantitatively. We survey the vast terrain of 'culturomics,' focusing on linguistic and cultural phenomena that were reflected in the English language between 1800 and 2000. We show how this approach can provide insights about fields as diverse as lexicography, the evolution of grammar, collective memory, the adoption of technology, the pursuit of fame, censorship, and historical epidemiology. Culturomics extends the boundaries of rigorous quantitative inquiry to a wide array of new phenomena spanning the social sciences and the humanities.

If you think about the classes you expect to take when studying linguistics in graduate school, probability theory is unlikely to be on the list. However, recent work in linguistics and cognitive science has begun to show that probability theory, combined with the methods of computer science and statistics, is surprisingly effective in explaining aspects of how people produce and interpret sentences (13), how language might be learned (46), and how words change over time (7, 8). The paper by Piantadosi et al. (9) that appears in PNAS adds to this literature, using probabilistic models estimated from large databases to update a classic result about the length of words.

We demonstrate a substantial improvement on one of the most celebrated empirical laws in the study of language, Zipf's 75-y-old theory that word length is primarily determined by frequency of use. In accord with rational theories of communication, we show across 10 languages that average information content is a much better predictor of word length than frequency. This indicates that human lexicons are efficiently structured for communication by taking into account interword statistical dependencies. Lexical systems result from an optimization of communicative pressures, coding meanings efficiently given the complex statistics of natural language use.

It is supposed that humans are genetically predisposed to be able to recognize sequences of context-free grammars with centre-embedded recursion while other primates are restricted to the recognition of finite state grammars with tail-recursion. Our aim was to construct a minimalist neural network that is able to parse artificial sentences of both grammars in an efficient way without using the biologically unrealistic backpropagation algorithm. The core of this network is a neural stack-like memory where the push and pop operations are regulated by synaptic gating on the connections between the layers of the stack. The network correctly categorizes novel sentences of both grammars after training. We suggest that the introduction of the neural stack memory will turn out to be substantial for any biological 'hierarchical processor' and the minimalist design of the model suggests a quest for similar, realistic neural architectures.

Abstract The first objective of this study was to compare the brain network engaged by preference classification and the standard grammaticality classification after implicit artificial syntax acquisition by re-analyzing previously reported event-related fMRI data. The results ...

We propose that the cognitive mechanisms that enable the transmission of cultural knowledge by communication between individuals constitute a system of ‘natural pedagogy’ in humans, and represent an evolutionary adaptation along the hominin lineage. We discuss three kinds of arguments that support this hypothesis. First, natural pedagogy is likely to be human-specific: while social learning and communication are both widespread in non-human animals, we know of no example of social learning by communication in any other species apart from humans. Second, natural pedagogy is universal: despite the huge variability in child-rearing practices, all human cultures rely on communication to transmit to novices a variety of different types of cultural knowledge, including information about artefact kinds, conventional behaviours, arbitrary referential symbols, cognitively opaque skills and know-how embedded in means-end actions. Third, the data available on early hominin technological culture are more compatible with the assumption that natural pedagogy was an independently selected adaptive cognitive system than considering it as a by-product of some other human-specific adaptation, such as language. By providing a qualitatively new type of social learning mechanism, natural pedagogy is not only the product but also one of the sources of the rich cultural heritage of our species.

Abstract Historical inference is at its most powerful when independent lines of evidence can be integrated into a coherent account. Dating linguistic and cultural lineages can potentially play a vital role in the integration of evidence from linguistics, anthropology, archaeology ...

The paper surveys recent research on language evolution, focusing in particular on models of cultural evolution and how they are being developed and tested using agent-based computational simulations and robotic experiments. The key challenges for evolutionary theories of language are outlined and some example results are discussed, highlighting models explaining how linguistic conventions get shared, how conceptual frameworks get coordinated through language, and how hierarchical structure could emerge. The main conclusion of the paper is that cultural evolution is a much more powerful process that usually assumed, implying that less innate structures or biases are required and consequently that human language evolution has to rely less on genetic evolution.

Patterns of word use both reflect and influence a myriad of human activities and interactions. Like other entities that are reproduced and evolve, words rise or decline depending upon a complex interplay between their intrinsic properties and the environments in which they function. Using Internet discussion communities as model systems, we define the concept of a word niche as the relationship between the word and the characteristic features of the environments in which it is used. We develop a method to quantify two important aspects of the size of the word niche: the range of individuals using the word and the range of topics it is used to discuss. Controlling for word frequency, we show that these aspects of the word niche are strong determinants of changes in word frequency. Previous studies have already indicated that word frequency itself is a correlate of word success at historical time scales. Our analysis of changes in word frequencies over time reveals that the relative sizes of word niches are far more important than word frequencies in the dynamics of the entire vocabulary at shorter time scales, as the language adapts to new concepts and social groupings. We also distinguish endogenous versus exogenous factors as additional contributors to the fates of words, and demonstrate the force of this distinction in the rise of novel words. Our results indicate that short-term nonstationarity in word statistics is strongly driven by individual proclivities, including inclinations to provide novel information and to project a distinctive social identity.

The voluntary control of phonation is a crucial achievement in the evolution of speech. In humans, ventral premotor cortex (PMv) and Broca's area are known to be involved in voluntary phonation. In contrast, no neurophysiological data are available about the role of the oro-facial sector of nonhuman primates PMv in this function. In order to address this issue, we recorded PMv neurons from two monkeys trained to emit coo-calls. Results showed that a population of motor neurons specifically fire during vocalization. About two thirds of them discharged before sound onset, while the remaining were time-locked with it. The response of vocalization-selective neurons was present only during conditioned (voluntary) but not spontaneous (emotional) sound emission. These data suggest that the control of vocal production exerted by PMv neurons constitutes a newly emerging property in the monkey lineage, shedding light on the evolution of phonation-based communication from a nonhuman primate species.

Background Archaeologists and anthropologists have long recognized that different cultural complexes may have distinct descent histories, but they have lacked analytical techniques capable of easily identifying such incongruence. Here, we show how Bayesian phylogenetic analysis can be used to identify incongruent cultural histories. We employ the approach to investigate Iranian tribal textile traditions. Methods We used Bayes factor comparisons in a phylogenetic framework to test two models of cultural evolution: the hierarchically integrated system hypothesis and the multiple coherent units hypothesis. In the hierarchically integrated system hypothesis, a core tradition of characters evolves through descent with modification and characters peripheral to the core are exchanged among contemporaneous populations. In the multiple coherent units hypothesis, a core tradition does not exist. Rather, there are several cultural units consisting of sets of characters that have different histories of descent. Results For the Iranian textiles, the Bayesian phylogenetic analyses supported the multiple coherent units hypothesis over the hierarchically integrated system hypothesis. Our analyses suggest that pile-weave designs represent a distinct cultural unit that has a different phylogenetic history compared to other textile characters. Conclusions The results from the Iranian textiles are consistent with the available ethnographic evidence, which suggests that the commercial rug market has influenced pile-rug designs but not the techniques or designs incorporated in the other textiles produced by the tribes. We anticipate that Bayesian phylogenetic tests for inferring cultural units will be of great value for researchers interested in studying the evolution of cultural traits including language, behavior, and material culture.

Human languages evolve continuously, and a puzzling problem is how to reconcile the apparent robustness of most of the deep linguistic structures we use with the evidence that they undergo possibly slow, yet ceaseless, changes. Is the state in which we observe languages today closer to what would be a dynamical attractor with statistically stationary properties or rather closer to a non-steady state slowly evolving in time? Here we address this question in the framework of the emergence of shared linguistic categories in a population of individuals interacting through language games. The observed emerging asymptotic categorization, which has been previously tested - with success - against experimental data from human languages, corresponds to a metastable state where global shifts are always possible but progressively more unlikely and the response properties depend on the age of the system. This aging mechanism exhibits striking quantitative analogies to what is observed in the statistical mechanics of glassy systems. We argue that this can be a general scenario in language dynamics where shared linguistic conventions would not emerge as attractors, but rather as metastable states.

Historical linguistics aims at inferring the most likely language phylogenetic tree starting from information concerning the evolutionary relatedness of languages. The available information are typically lists of homologous (lexical, phonological, syntactic) features or characters for many different languages: a set of parallel corpora whose compilation represents a paramount achievement in linguistics.

From this perspective the reconstruction of language trees is an example of inverse problems: starting from present, incomplete and often noisy, information, one aims at inferring the most likely past evolutionary history. A fundamental issue in inverse problems is the evaluation of the inference made. A standard way of dealing with this question is to generate data with artificial models in order to have full access to the evolutionary process one is going to infer. This procedure presents an intrinsic limitation: when dealing with real data sets, one typically does not know which model of evolution is the most suitable for them. A possible way out is to compare algorithmic inference with expert classifications. This is the point of view we take here by conducting a thorough survey of the accuracy of reconstruction methods as compared with the Ethnologue expert classifications. We focus in particular on state-of-the-art distance-based methods for phylogeny reconstruction using worldwide linguistic databases.

In order to assess the accuracy of the inferred trees we introduce and characterize two generalizations of standard definitions of distances between trees. Based on these scores we quantify the relative performances of the distance-based algorithms considered. Further we quantify how the completeness and the coverage of the available databases affect the accuracy of the reconstruction. Finally we draw some conclusions about where the accuracy of the reconstructions in historical linguistics stands and about the leading directions to improve it.

The evolutionary origin of human language and its neurobiological foundations has long been the object of intense scientific debate. Although a number of theories have been proposed, one particularly contentious model suggests that human language evolved from a manual gestural communication system in a common ape-human ancestor. Consistent with a gestural origins theory are data indicating that chimpanzees intentionally and referentially communicate via manual gestures, and the production of manual gestures, in conjunction with vocalizations, activates the chimpanzee Broca's area homologue a region in the human brain that is critical for the planning and execution of language. However, it is not known if this activity observed in the chimpanzee Broca's area is the result of the chimpanzees producing manual communicative gestures, communicative sounds, or both. This information is critical for evaluating the theory that human language evolved from a strictly manual gestural system. To this end, we used positron emission tomography (PET) to examine the neural metabolic activity in the chimpanzee brain. We collected PET data in 4 subjects, all of whom produced manual communicative gestures. However, 2 of these subjects also produced so-called attention-getting vocalizations directed towards a human experimenter. Interestingly, only the two subjects that produced these attention-getting sounds showed greater mean metabolic activity in the Broca's area homologue as compared to a baseline scan. The two subjects that did not produce attention-getting sounds did not. These data contradict an exclusive gestural origins theory for they suggest that it is vocal signaling that selectively activates the Broca's area homologue in chimpanzees. In other words, the activity observed in the Broca's area homologue reflects the production of vocal signals by the chimpanzees, suggesting thast this critical human language region was involved in vocal signaling in the common ancestor of both modern humans and chimpanzees.

This paper proposes a coevolutionary scenario on the origins of compositionality and word order regularity in human language, and illustrates it using a multi-agent, behavioral model. The model traces a bottom-up process of syntactic development; artificial agents, by iterating local orders among lexical items, gradually build up basic constituent word order(s) in sentences. These results show that structural features of language (e.g. syntactic categories and word orders) could have coevolved with lexical items, as a consequence of general learning mechanisms (e.g. pattern extraction and sequential learning) initially not language-specific.

We show how the prevailing majority opinion in a population can be rapidly reversed by a small fraction p of randomly distributed committed agents who consistently proselytize the opposing opinion and are immune to influence. Specifically, we show that when the committed fraction grows beyond a critical value p(c) ≈ 10%, there is a dramatic decrease in the time T(c) taken for the entire population to adopt the committed opinion. In particular, for complete graphs we show that when p < pc, T(c) ~ exp [α(p)N], whereas for p>p(c), T(c) ~ ln N. We conclude with simulation results for Erdős-Rényi random graphs and scale-free networks which show qualitatively similar behavior.

Zipf’s law seems to be ubiquitous in human languages and appears to be a universal property of complex communicating systems. Following the early proposal made by Zipf concerning the presence of a tension between the efforts of speaker and hearer in a communication system, we introduce evolution by means of a variational approach to the problem based on Kullback’s Minimum Discrimination of Information Principle. Therefore, using a formalism fully embedded in the framework of information theory, we demonstrate that Zipf’s law is the only expected outcome of an evolving communicative system under a rigorous definition of the communicative tension described by Zipf.

The naming game (NG)[1, 2] describes a population of agents playing pairwise interactions in order to negotiate conventions. Following Wittgenstein's intuition on language [3], the negotiation is seen as an activity in which one of the individuals (ie, the “speaker”) tries to ...

Time and space are fundamental to human language and embodied cognition. In our early work we investigated how Lingodroids, robots with the ability to build their own maps, could evolve their own geopersonal spatial language. In subsequent studies we extended the framework developed for learning spatial concepts and words to learning temporal intervals. This paper considers a new aspect of time, the naming of concepts like morning, afternoon, dawn, and dusk, which are events that are part of day-night cycles, but are not defined by specific time points on a clock. Grounding of such terms refers to events and features of the diurnal cycle, such as light levels. We studied event-based time in which robots experienced day-night cycles that varied with the seasons throughout a year. Then we used meet-at tasks to demonstrate that the words learned were grounded, where the times to meet were morning and afternoon, rather than specific clock times. The studies show how words and concepts for a novel aspect of cyclic time can be grounded through experience with events rather than by times as measured by clocks or calendars.

A long-standing debate concerns whether humans are specialized for speech perception [1, 2, 3, 4, 5, 6 and 7], which some researchers argue is demonstrated by the ability to understand synthetic speech with significantly reduced acoustic cues to phonetic content [2, 3, 4 and 7]. We tested a chimpanzee (Pan troglodytes) that recognizes 128 spoken words [ 8 and 9], asking whether she could understand such speech. Three experiments presented 48 individual words, with the animal selecting a corresponding visuographic symbol from among four alternatives. Experiment 1 tested spectrally reduced, noise-vocoded (NV) synthesis, originally developed to simulate input received by human cochlear-implant users [10]. Experiment 2 tested “impossibly unspeechlike” [3] sine-wave (SW) synthesis, which reduces speech to just three moving tones [11]. Although receiving only intermittent and noncontingent reward, the chimpanzee performed well above chance level, including when hearing synthetic versions for the first time. Recognition of SW words was least accurate but improved in experiment 3 when natural words in the same session were rewarded. The chimpanzee was more accurate with NV than SW versions, as were 32 human participants hearing these items. The chimpanzee's ability to spontaneously recognize acoustically reduced synthetic words suggests that experience rather than specialization is critical for speech-perception capabilities that some have suggested are uniquely human [ 12, 13 and 14].

Evolution is a process by which change occurs through replication. Variation can be introduced into a population during the replication process. Some of the resulting variants may be replicated more rapidly than others, and so the characteristics of the population – and individuals within it – change over time. These processes can be recognised most obviously in genetics and ecology; but they also arise in the context of cultural change. We discuss two key questions that are crucial to the development of evolutionary theory. First, we consider how different application domains may be usefully placed within a single framework; and second, we ask how one can distinguish directed, deterministic change from changes that occur purely because of the stochastic nature of the underlying replication process.

This paper reconsiders the diphone-based word segmentation model of Cairns, Shillcock, Chater, and Levy (1997) and Hockema (2006), previously thought to be unlearnable. A statistically principled learning model is developed using Bayes theorem and reasonable assumptions about infants implicit knowledge. The ability to recover phrase-medial word boundaries is tested using phonetic corpora derived from spontaneous interactions with children and adults. The (unsupervised and semi-supervised) learning models are shown to exhibit several crucial properties. First, only a small amount of language exposure is required to achieve the model's ceiling performance, equivalent to between 1day and 1month of caregiver input. Second, the models are robust to variation, both in the free parameter and the input representation. Finally, both the learning and baseline models exhibit undersegmentation, argued to have significant ramifications for speech processing as a whole.

Coding plays a universal and pervasive role in biological organization, in forms such as genetic coding (DNA to protein translation), RNA processing, gene regulation, protein modification, cell signalling, immune responses, epigenetic development and natural language. Nevertheless, the ways and means by which organic codes are formed and used are still poorly understood. A formal model is presented in this paper to investigate the emergence of conventional codes among code users. The relationship between the formation and the usage of codes is discussed, and a biological mechanism involving coding is identified in the context of the immune system.

Variations in the material culture in Africa in the Late Pleistocene indicate that it was a period of rapid cultural change not previously observed in the Middle Stone Age. In southern Africa, two techno-traditions, the Still Bay and the Howiesons Poort, have raised interest because ...

Cumulative cultural evolution requires that information is faithfully transmitted from generation to generation. The present study examines the role of agent interaction as a social learning mechanism through which information is transmitted across multiple generations. The performance of two types of linear transmission chains was compared: noninteractive (agents in adjacent chain positions were not permitted to interact) and interactive (adjacent agents freely interacted with one another). In both conditions, information (details of a narrative text) was lost as it was passed along the transmission chain. However, interactive transmission chains promoted more accurate recall of information than noninteractive chains. A content analysis revealed that most listeners actively participated in the information transfer process by seeking clarification and providing backchannel feedback to the narrator. Furthermore, the extent to which listeners engaged with the narrator was associated with narrator recall accuracy. Our results indicate that bidirectional agent interaction is an important consideration for studies of cultural transmission and cumulative cultural evolution.

In this study, the complex-network approaches are employed to investigate the word form networks and the lemma networks extracted from dependency syntactic treebanks of fifteen different languages. The results show that it is possible to classify human languages by means of the main parameters of complex networks. The complex-network approaches can obtain language classifications as precise as achieved by contemporary word order typology. Clustering experiments point to the fact that the difference between the word form networks and the lemma networks can make for a better classification of languages. In short, the dependency syntactic networks can reflect morphological variation degrees and morphological complexity.

Language dynamics is a rapidly growing field that focuses on all processes related to the emergence, evolution, change and extinction of languages. Recently, the study of self-organization and evolution of language and meaning has led to the idea that a community of language users can be seen as a complex dynamical system, which collectively solves the problem of developing a shared communication framework through the back-and-forth signaling between individuals.

We shall review some of the progress made in the past few years and highlight potential future directions of research in this area. In particular, the emergence of a common lexicon and of a shared set of linguistic categories will be discussed, as examples corresponding to the early stages of a language. The extent to which synthetic modeling is nowadays contributing to the ongoing debate in cognitive science will be pointed out. In addition, the burst of growth of the web is providing new experimental frameworks. It makes available a huge amount of resources, both as novel tools and data to be analyzed, allowing quantitative and large-scale analysis of the processes underlying the emergence of a collective information and language dynamics.

Cognitive Robotics can be defined as the study of cognitive phenomena by their modeling in physical artifacts such as robots. This is a very lively and fascinating field which has already given fundamental contributions to our understanding of natural cognition. Nonetheless, robotics has to date addressed mainly very basic, low-level cognitive phenomena like sensory-motor coordination, perception, and navigation, and it is not clear how the current approach might scale up to explain high-level human cognition. In this paper we argue that a promising way to do that is to merge current ideas and methods of embodied cognition with the Russian tradition of theoretical psychology which views language not only as a communication system but also as a cognitive tool, that is by developing a Vygotskyan cognitive robotics. We substantiate this idea by discussing several domains in which language can improve basic cognitive abilities and permit the development of high-level cognition: learning, categorization, abstraction, memory, voluntary control, and mental life.

Evolutionary musicologists agree that music is an enigma. Existing theories contradict each other, and cannot explain mechanisms or functions of musical emotions in workings of the mind, nor evolutionary reasons for music origins. Based on a synthesis of cognitive science and mathematical models of the mind this paper proposes a hypothesis of a fundamental role of music in cognition, and evolution of the mind, consciousness, and cultures. We consider a split in the vocalizations of proto-humans into two types: one less emotional and more concretely-semantic, evolving into language, and the other preserving emotional connections along with semantic ambiguity, evolving into music. The proposed hypothesis departs from other theories in considering specific mechanisms of the mind-brain, which required the evolution of music parallel with the evolution of cultures and languages. Arguments are presented that the evolution of language toward becoming the semantically powerful tool of today required emancipation from emotional encumbrances. The opposite, no less powerful mechanisms required a compensatory evolution of music toward more differentiated and refined emotionality. Fast differentiation of knowledge due to language created cognitive dissonances among knowledge and instincts. Differentiated emotions were needed for resolving these dissonances. Thus the need for refined music in the process of cultural evolution is grounded in fundamental mechanisms of the mind. This is why today’s human mind and cultures cannot exist without today’s music. The proposed hypothesis gives a basis for future analysis of why different evolutionary paths of languages were paralleled by different evolutionary paths of music. We consider empirical data on parallel evolution of cognition, consciousness, and music during the last three thousand years. Existing data on changes in consciousness and musical styles support the proposed hupothesis. We compare musical emotions to emotions of language prosody, and emotions of cognitive dissonances. Then we propose experimental approaches toward verification of this hypothesis in psychological and neuroimaging research.

It is commonly assumed that patterns of syncretism in inflectional paradigms are restricted in some way. In this article, I show how such restrictions can reflect cognitive constraints on language learning. Namely, I construct a learning algorithm that is biased toward certain ...

Purpose of the review A reduced dosage of the transcription factor FOXP2 leads to speech and language impairments probably owing to deficits in cortical and subcortical neural circuits. Based on evolutionary sequence analysis it has been proposed that the two amino acid substitutions that occurred on the human lineage have been positively selected. Here I review recent studies investigating the functional consequences of these two substitutions and discuss how these first endeavors to study human brain evolution can be interpreted in the context of speech and language evolution. Recent findings Mice carrying the two substitutions in their endogenous Foxp2 gene show specific alterations in dopamine levels, striatal synaptic plasticity and neuronal morphology. Mice carrying only one functional Foxp2, show additional and partly opposite effects suggesting that FOXP2 has contributed to tuning cortico-basal ganglia circuits during human evolution. Evidence from human and songbird studies suggest that this could have been relevant during language acquisition or vocal learning, respectively. Summary FOXP2 could have contributed to the evolution of human speech and language by adapting cortico-basal ganglia circuits. More generally the recent studies allow careful optimism that aspects of human brain evolution can be investigated in model systems such as the mouse.

Nicholls and Gray have described a phylogenetic model for trait data. They used their model to estimate branching times on Indo-European language trees from lexical data. Alekseyenko and co-workers extended the model and gave applications in genetics. We extend the inference to handle data missing at random. When trait data are gathered, traits are thinned in a way that depends on both the trait and the missing data content. Nicholls and Gray treated missing records as absent traits. Hittite has 12% missing trait records. Its age is poorly predicted in their cross-validation. Our prediction is consistent with the historical record. Nicholls and Gray dropped seven languages with too much missing data. We fit all 24 languages in the lexical data of Ringe and co-workers. To model spatiotemporal rate heterogeneity we add a catastrophe process to the model. When a language passes through a catastrophe, many traits change at the same time. We fit the full model in a Bayesian setting, via Markov chain Monte Carlo sampling. We validate our fit by using Bayes factors to test known age constraints. We reject three of 30 historically attested constraints. Our main result is a unimodal posterior distribution for the age of Proto-Indo-European centred at 8400 years before Present with 95% highest posterior density interval equal to 7100-9800 years before Present.

We present an incremental model of lexicon consensus in a population of simulated agents. The emergent lexicon is evolved with a hybrid algorithm which is based on grammatical evolution with semantic rules and reinforcement learning. The incremental model allows to add subsequently new agents and objects to the environment when a consensual language has emerged for a steady set of agents and objects. The main goal in the proposed system is to test whether the emergent lexicon can be maintained during the execution when new agents and object are added. The proposed system is completely based on grammars and the results achieved in the experiments show how building a language starting from a grammar can be a promising method in order to develop artificial languages.

We analyzed 40 single nucleotide polymorphism and 19 short tandem repeat Y-chromosomal markers in a large sample of 1,525 indigenous individuals from 14 populations in the Caucasus and 254 additional individuals representing potential source populations. We also employed a lexicostatistical approach to reconstruct the history of the languages of the North Caucasian family spoken by the Caucasus populations. We found a different major haplogroup to be prevalent in each of four sets of populations that occupy distinct geographic regions and belong to different linguistic branches. The haplogroup frequencies correlated with geography and, even more strongly, with language. Within haplogroups, a number of haplotype clusters were shown to be specific to individual populations and languages. The data suggested a direct origin of Caucasus male lineages from the Near East, followed by high levels of isolation, differentiation, and genetic drift in situ. Comparison of genetic and linguistic reconstructions covering the last few millennia showed striking correspondences between the topology and dates of the respective gene and language trees and with documented historical events. Overall, in the Caucasus region, unmatched levels of gene–language coevolution occurred within geographically isolated populations, probably due to its mountainous terrain.

The study of properties of speech sound systems is of great significance in understanding the human cognitive mechanism and the working principles of speech sound systems. Some properties of speech sound systems, such as the listener-oriented feature and the talker-oriented feature, have been unveiled with the statistical study of phonemes in human languages and the research of the interrelations between human articulatory gestures and the corresponding acoustic parameters. With all the phonemes of speech sound systems treated as a coherent whole, our research, which focuses on the dynamic properties of speech sound systems in operation, investigates some statistical parameters of Chinese phoneme networks based on real text and dictionaries. The findings are as follows: phonemic networks have high connectivity degrees and short average distances; the degrees obey normal distribution and the weighted degrees obey power law distribution; vowels enjoy higher priority than consonants in the actual operation of speech sound systems; the phonemic networks have high robustness against targeted attacks and random errors. In addition, for investigating the structural properties of a speech sound system, a statistical study of dictionaries is conducted, which shows the higher frequency of shorter words and syllables and the tendency that the longer a word is, the shorter the syllables composing it are. From these structural properties and dynamic properties one can derive the following conclusion: the static structure of a speech sound system tends to promote communication efficiency and save articulation effort while the dynamic operation of this system gives preference to reliable transmission and easy recognition. In short, a speech sound system is an effective, efficient and reliable communication system optimized in many aspects.

The ability of humans to communicate via language is a complex, adapted phenotype, which undoubtedly has a recently evolved genetic component. However, the evolutionary dynamics of language-associated alleles are poorly understood. To improve our knowledge of such systems, a population-genetics model for language-associated genes is developed. (The model is general and applicable to social interactions other than communication.) When an allele arises that potentially improves the ability of individuals to communicate, it will experience positive frequency-dependent selection because its fitness will depend on how many other individuals communicate the same way. Consequently, new and rare alleles are selected against, posing a problem for the evolutionary origin of language. However, the model shows that if individuals form language-based cliques, then novel language-associated alleles can sweep through a population. Thus, the origin of language ability can be sufficiently explained by Darwinian processes operating on genetic diversity in a finite population of human ancestors.

The field of linguistics is concerned with the scientific study of language and its structure. Human language provides an unbounded range of discrete and distinct messages. These messages are produced voluntarily under cortical control, and are not bound to the presence of particular stimuli. The mechanism behind the unboundedness of language is based on two facts, which include that two distinct discrete combinatorial systems interact to allow for an unlimited set of messages grounded in a manageable inventory of meaningful sounds. One subsystem combines members of a small set of individually meaningless sounds according to the phonological pattern of the language into meaningful words, which are in turn combined by a quite distinct subsystem, the language's syntax, into phrases, clauses, and sentences. The recursive, hierarchical nature of such combination is the basis for its open-ended expressive capacity. Certain behavior that is learned or culturally transmitted may be selectionally advantageous under the conditions in which the organism finds itself. Selection may then operate to favor individuals who are able to learn the advantageous behavior rapidly and efficiently. The learned behavior may itself alter the characteristics of the environment within which selection occurs favoring its acquisition even more. Computer simulations have suggested that structure sensitivity can plausibly be expected to arise in communication.

The Mirror System Hypothesis of the evolution of the human language-ready brain emphasizes the parity requirement for communication through language. It gives key roles to mirror neurons for manual actions and the evolution of brain mechanisms for an imitation of the praxis. Both the imitation and language require integration of mirror neurons with diverse neural systems. The visual data on shape and pose of an object are processed in parietal cortex and passed to an area of the premotor cortex called F5. Many single neurons in F5 fire most strongly when the monkey executes a limited range of manual actions, with distinct neurons related to such as a precision pinch, tearing paper, or breaking peanuts. The Mirror System Hypothesis holds that the brain mechanisms, which support language, evolved in part by an elaboration of Broca's area atop the mirror system for manual action. The Mirror System Hypothesis has several elements such as language demands parity and mirror neurons provide a basis for parity. The hominin evolution mentions that mirror neurons for manual actions preceded those for vocal actions, thereby lending support to gestural theories of language origin. Ape gestures are flexible and learnable, in contrast to the mostly innate system of primate vocalizations, exemplifying processes whereby a practical action may become ritualized to serve as a communicative action. Imitation is essential for language and mirror neurons are essential for imitation but do not support imitation in and of themselves.

The basic processes of syntax are categorized into four main categories. These categories include a process for assembling words into hierarchical structures, processes for determining the boundaries of segments within such structures, and processes for moving segments within such structures and lastly, processes for determining the reference of elements that are not phonetically expressed. The syntax characterizes all languages, whether signed or spoken, in a highly developed form but it is entirely absent both from the productions of language-trained animals and the natural communication systems of other species. Children first acquire nouns, then a few verbs, and only later begin to add other word classes. The acquisition of grammatical items follows some time after the emergence of recognizable syntactic structures, even if those structures do not normally begin to appear until age two or thereabouts, and the earliest stages of development constitute an example of protolanguage, rather than full human language. The emergence of these structures is typically quite rapid with several types of both simple and complex sentence appearing within a few weeks. Creole languages are really a special case of child language development, representing what the language faculty produces when structured input is severely reduced.

Biolinguistics is a fairly broad research program that allow for the exploration of many avenues of research, including the formalist, functionalist, and nativist, and it insists on the uniqueness of the language faculty or alternatively, nativist about general (human) cognition, but not about language per se. It is assumed that the language faculty arose in Homo sapiens, and fairly recently, that is, within the last 200,000 years. The recent emergence of the language faculty is most compatible with the idea that at most one or two evolutionary innovations, combined with the cognitive resources available before the emergence of language, delivers the linguistic capacity much as it is known today. Biolinguists, especially those of a minimalist persuasion, have explored the possibility that some of the properties of language faculty may have emerged spontaneously, by the sheer force of biophysics. The type of principles by which minimalists seek to reanalyze the data captured by previous models are, quite plausibly, reflexes of computational laws that go well beyond the linguistic domain. All the linguistic models, no matter how minimalist, rely on the existence of lexical items. Numerous comparative studies in psychology reveal that mature linguistic creatures transcend many cognitive limits seen in animals and prelinguistic infants. Such limits are the signature limits of core knowledge systems, which correspond to primitive knowledge modules. Such systems suffer from informational encapsulation and quickly reach combinatorial limits.

This article provides an overview on infant-directed speech and language evolution. Infant-directed speech is defined as a set of speech registers that caretakers use to address infants. There are at least three different kinds of infant-directed speech, first, which is used to get the infant's attention, second, which is used to soothe the infant, and last, which is used to address the infant with linguistically meaningful utterances. All kinds of infant- directed speech are characterized by slower speech rate and larger intonation contours. Attention-getting infant-directed speech is characterized by higher volume and extreme intonation excursions, but it does not necessarily consist of meaningful utterances. Soothing infant-directed speech is characterized by lower volume, sometimes even whispered speech, and very flowing intonation contours. Caretakers use infant-directed speech automatically when addressing infants, even without being aware of doing it. They also automatically adapt the complexity of their speech to the level of linguistic competence of the infant. The infant-directed speech also appears to be nearly universal cross-culturally and a similar register is attested in signed languages. Computational experiments have revealed that it is easier to acquire vowel categories on the basis of infant-directed speech than on the basis of adult-directed speech. Other computational experiments have shown that infant-directed speech can help to preserve stability of vowel systems over time.

This article focuses on the two different levels that are used to define language. One of the levels is the individual level, where detailed individual behavior is studied and the other is the population level, where individual behavior is averaged and abstracted, and more general trends and processes are studied. Both these levels are intertwined and interdependent and such interaction between the levels can lead to a phenomenon called self- organization. Self-organization is the spontaneous emergence of order in a system that must be spontaneous. The interaction between self-organization and biological evolution is fundamental to understanding the evolution of language. Biological evolution determines the dynamics and the boundary conditions of the self-organizing process. Self-organization causes the language to converge on a limited number of states, the properties of which then determine the fitness of the language-using agents. Biological evolution then selects adaptations that help cope with the properties of the states resulting from self-organization. There are two perspectives on self-organization in language. First is the perspective of an individual's linguistic knowledge, in which linguistic items such as words or speech sounds can be considered as the microscopic level and the complete linguistic system can be considered as the macroscopic level. The second perspective is that of language in a population of speakers, where individual language users constitute the microscopic level, and the whole language community constitutes the macroscopic level.

This article focuses on the inference that the Middle Stone Age (MSA) inhabitants of Blombos Cave had fully syntactic language. The Blombos inference is seen to use three consecutive inferential steps as, from data about a number of material objects, it draws a conclusion about a facet of language evolution. One of the steps inferred that the shells were beads worn by the humans who inhabited Blombos Cave some 75 kya. It was inferred from data and/or assumptions about properties of a number of MSA tick shells. The data and/or assumptions are about properties of forty-one shells of the scavenging gastropod Nassarius kraussianus. These properties of the shells include their age, their man-made perforations, their flattened facets, and their distribution in groups in the cave. Another step inferred that the humans were engaged in symbolic behavior, which was from data and/or assumptions about the beads. Another step inferred that the humans had fully syntactic language. It was inferred from data and/or assumptions about the symbolic behavior. The symbols-to-syntax inference needs to meet a number of fundamental conditions, including the one that is the warrantedness condition, which states that the inferential step leading to some conclusion about language evolution needs to be suitably warranted or licensed.

This article explains the evolution of capacity for learning a language in the human species. Several essential cognitive capacities had to be developed before language could even begin. First, language rests on a rich conceptual system. One must be able to perceive patterns in the objects and events around in order to learn a word or to use. One must learn arbitrary associations between vocalizations or gestures and concepts to understand or to use even isolated words. A typical word in any human language that is used today is a conventional three-way association between a meaning, a distinctive sound sequence and a characteristic set of syntactic roles. The ability to make arbitrary associations between meanings and either sound or gestures is not quite limited to human beings. When coached by humans, dogs can learn to respond to several hand signals or spoken commands, and apes can do much better than dogs, but no animal can learn words with the voracious ease of human beings. Language must have begun with the ability to associate gestures or vocalizations with concepts, and to use these vocalizations or gestures as a means of sharing our concepts with others. The brains have evolved over the years to store a huge number of words.

The article demonstrates many aspects of grammar that can be derived from domain-general cognitive processes, especially those of neuromotor automation, chunking, categorization, inference-making, and cross-modal association. Construction grammar posits a direct connection between the conventionalized constructions of a language and their meanings. All constructions have some specific lexical or grammatical material in them. Construction grammar emphasizes the interaction of the lexicon with the syntax. The domain-general processes involved in construction formation and use are sequential processing and categorization. Sequential processing or chunking is the process by which repeated sequences of experience (words or other events) come to be grouped together in memory as units that can be accessed directly. Categorization is necessary to the cognitive representations of constructions in several ways. First, categorization is necessary for the recognition that an element or sequence is the same as one previously experienced. Second, categorization is used to develop the schematic slots of constructions. Constructions are created through the repetition and thus conventionalization of useful sequences of elements and their meanings arise from associations with the context and implications that are present. The most pervasive process by which new constructions are created is grammaticalization, in which a new construction is created along with a new grammatical morpheme and the latter evolves from a lexical morpheme or combinations of grammatical and lexical morphemes.

A robotic and embodied approach to the modeling of the evolution of language addresses various aspects of language origins such as prelinguistic social coordination, signaling behavior, and the emergence of compositional lexicons. Robot language experiments typically involve tasks in which the robots must communicate about objects and entities in the environment, about their physical interaction with objects, and about their body posture. Embodied agents are multiagent systems in which a population of simulated agents live in a shared environment, can receive visual, auditory, and tactile information about the world, and can act on it. These experiments typically involve communication about spatial navigation and foraging tasks. Robotic and embodied agent models have made significant contributions to the understanding of genetic and cultural evolution dynamics in language origins, where both the semantic system and the lexicon interact and co-adapt during linguistic evolution. Robotics models have mostly focused on the emergence of shared lexicons through cultural evolution. Simulated embodied agent models have mostly investigated the genetic evolution of shared languages. Simulation models of embodied agents have been employed to model the genetic evolution of shared lexicons. The embodied modeling approach has also been employed specifically to look at the evolutionary emergence of syntax, with particular focus on compositionality. Embodied multiagent systems have also been used for modeling the cultural evolution of syntax.

This article explores the connection of the molecular evidence of evolutionary relationships between the various hominins with fossil evidence from the Plio- Pleistocene times, a period covering episodes of immense swings in temperature and rainfall, beginning about 5.5 million years ago (mya) and ending only about 11 kya. New technologies, allowing analysis of trace amounts of genetic material from human fossils, may help determine these relationships such as mitochondrial DNA indicates that widely-dispersed human groups apparently split into at least two descendant populations in the late Middle Pleistocene, perhaps during the period of global climate extremes 480-425 kya. The principle of a molecular clock underlies the use of DNA sequences or their derivatives as cellular fossils to aid reconstruction of speciation events. The estimation of mutation rates for nuclear (chromosomal) DNA is difficult because chromosomes, and the DNA which composes them, recombine and homogenize DNA sequences in every new generation, in addition to undergoing single base substitutions. The overall mutation rate for mitochondrial genes is about 2% every million years. Molecular dates using nuclear gene data support an early Miocene divergence for Asian and African apes at 18 mya, but mitochondrial timescales are younger, by 45 million years. It appears that the African great apes are the closest genetic relatives of humans, with estimated splits based on fossils between Homo and Pan dating from 67.5 mya.

Grammaticalization theory has become an influential theory within historical linguistics. Grammaticalization is the process whereby open-class lexical items develop over time into closed-class items with grammatical functions. It is said to be a uniform series of semantic changes involving metaphorical usage such as spatial terms acquire temporal meanings but not vice versa and bleaching. Grammaticalization often leads to morphologization, which is an independent marker of tense or where a number becomes an affix rather than remaining a free wordform, and may even ultimately fuse with the root of the lexeme to which it is attached. It is always possible for grammaticalization to stop short of morphologization that applies to most of the languages of East Asia. Even without any syntax there could be phonological processes operating between regularly contiguous words, and some of these processes could in due course become opaque. This would give rise to situations where the same meaning was expressed by two or more forms in different contexts that is, to instances of synonymy. Even without syntax, some items could be regularly juxtaposed to express a consistent conventionalized meaning. The capacity for allomorphy and morphophonological alternation could have arisen alongside syntax or even before it, but at any rate independently of it.

This article deals with the evolution of natural languages and examines artificial or imaginary languages that supply material for evolutionary- linguistic thought-experiments. The term creole has been used in a variety of ways. One usage links its definition to that of pidgin. A pidgin language has been defined as a rudimentary language even if to some degree it is an institutionalized form of language used between speakers whose mother tongues are mutually incomprehensible. A creole is then a pidgin that has acquired native speakers such as children surrounded by adults that belong to different speech communities and therefore talk to each other most of the time in pidgin. One of the group of researchers compared human cognitive and communicative capacities with those of animals. They attempted to identify what is contained in the faculty of language in the narrow sense (FLN), that is, those characteristics or capacities that are both peculiar to humans and peculiar to language. They suggest that the FLN may turn out to be limited to a sole characteristic, namely recursion. The vocabulary of one of the languages, monocategoric, contains two classes of items that include simple expressions, such as snake, you, John, Mary, and story, and operators. Operators may be one-place, two-place, three-place or in principle n-place for any n > 0. A well-formed expression in monocategoric is any simple expression or any complex expression formed from one or more other expressions (whether simple or complex) followed by an appropriate operator.

This article addresses the logical problem of language evolution that arises from a conventional universal grammar (UG) perspective and investigates the biological and cognitive constraints that are considered when explaining the cultural evolution of language. The UG prespective states that language acquisition should not be viewed as a process of learning at all but it should be viewed as a process of growth, analogous to the growth of the arm or the liver. UG is intended to characterize a set of universal grammatical principles that hold across all languages. Language has the same status as other cultural products, such as styles of dress, art, music, social structure, moral codes, or patterns of religious beliefs. Language may be particularly central to culture and act as the primary vehicle through which much other cultural information is transmitted. The biological and cognitive constraints helps to determine which types of linguistic structure tend to be learned, processed, and hence transmitted from person to person, and from generation to generation. The communicative function of language is likely to shape language structure in relation to the thoughts that are transmitted and regarding the processes of pragmatic interpretation that people use to understand each other's behavior. A source of constraints derives from the nature of cognitive architecture, including learning, processing, and memory. The language processing involves generating and decoding regularities from highly complex sequential input, indicating a connection between general-purpose cognitive mechanisms for learning and processing sequential material, and the structure of natural language.

This article proposes the important prerequisites for indirect speech that includes at least four major cognitive factors, adequate phonological storage capacity, recursion, a full theory of mind, and executive functions. The phonological store subsystem is considered to play a critical role in language production and comprehension. Adults who have greater phonological storage capacity have also been found to score higher on verbal tests of intelligence and higher on measures of verbal fluency and they also do better on retroactive and proactive interference tasks. The phonological storage capacity represents a short-term memory ensemble that can be phylogenetically tracked to earlier homologues in hominin evolution and to current primate brain systems. The recursion is highly dependent upon the phonological storage capacity. The theory of mind refers to the ability to infer the thoughts, emotions, and intentions of others. The theory of mind also consists of four independent skills that include detection of the intentions of others, detection of eye-direction, shared attention, and the final component called the theory of mind module. The final component, whose onset in humans is thought to develop by the age of four, contains a complex set of social-cognitive rules, and combined with the other three components, creates the full-fledged, adult-like theory of mind. The specific executive function might be involved in the theory of mind.

This article explores the origins of language in manual gestures. Humans have the capacity to produce complex intentional gestures either vocally or manually and either system can serve as the medium for language. Vocal learning is especially critical to speech, and few non-human primate species appear capable of more than limited vocal learning. Studies suggest that primate calls show limited modifiability, but its basis remains unclear, and it is apparent in subtle changes within call types rather than the generation of new call types. The discovery of mirror neurons in area F5 of primate prefrontal cortex further supports the evolutionary priority of manual gesture. The hands and arms would lend themselves naturally to mimed representation of events in bipedal hominins. Mime is fundamentally imitative, in that there is a mapping between the mimed action and what it represents. Modern signed languages retain a strong mimetic, or iconic, component such as in Italian sign language some 50% of hand signs and 67% of the bodily locations of signs stem from iconic representations. The addition of phonation, perhaps through selection for a FOXP2 mutation, would allow non-visible gestures within the mouth, including movements of the larynx, velum and tongue, to be recovered from the acoustic signal, as proposed by the motor theory of speech perception.

This article explains the concept of symbolic reference. Symbolic reference is a distinguishing feature of human language, in contrast with species-typical vocalizations and communicative gestures. The symbolic reference must be acquired by learning, and lacks both the natural associations and trans- generational reproductive consequences that would make such references biologically evolvable. The absence of natural constraints also facilitates the capacity for distinct symbol combinations to determine unique references. The asymmetric relationship between features of the sign vehicle and features of the referential relationship explains that conventional typographical characters can refer both symbolically and non-symbolically. A complex sign vehicle such as the diagram of an electronic circuit can serve as an icon even though it is composed of symbols. Once the many symbolic sign components are interpreted, their collective configuration is seen as iconic of the organization of the physical circuit that is relevant to language. The combinatorial organization of symbolic legisigns comprising a phrase, sentence, or narrative may constitute a higher order iconic, indexical, or symbolic referential function. The basis of the symbolic reference of words is the systematicity that unifies the network of indexical relationships that they constitute and depend upon. The network of indexical relationships is also reflexive, circular, and ultimately self- referential. The use of linguistic symbols such as words, to refer to specific objects, events, or properties of things, requires indexical mediation.

This article concentrates on the three genes of recent interest in the literature on language origins. These genes are microcephalin and ASPM, which cause microcephaly when disabled and FOXP2, which causes a severe speech and language disability when disrupted. The FOXP2 gene was isolated, sequenced, classified as a member of the forkhead box family, and named FOXP2 by the year 2001. The protein products of forkhead genes have forkhead DNA binding domains, which bind to specified regulatory sequences in other genes, and regulate the expression of these other genes. FOXP2 is expressed in the mouse brain during development, but is also expressed in a wide variety of mouse tissues. The gene has many essential roles in mammalian development and function that are totally unrelated to language. It was announced in the year 2005 that two genes essential for proper brain growth, microcephalin and ASPM, are undergoing a change. Microcephalin and ASPM proteins are crucial for proper brain development. Microcephalin is involved in regulating the cell cycle especially in relation to DNA repair before cell division. ASPM helps to align the mitotic spindles in the cell so that it divides symmetrically. The defective versions of microcephalin and ASPM result in microcephaly, a genetic disorder in which people have small heads and small brains.

This article focuses on one aspect of a comprehensive theory of human cognitive evolution, and that is mimesis. Mimesis is an embodied, analogue, and primordial mode of representation, in the sense that it is a preadaptation for language and also a self-sufficient cognitive adaptation in its own right, which accounts for some of the major features of human cultural and cognitive life. A mimetic act is a performance that reflects the perceived event structure of the world, and is the purest form of embodied representation. It has three behavioral manifestations that include rehearsal of skill, in which the actor imagines and reproduces previous performances with a view to improving them. Other include re-enactive mime, in which patterns of action, usually of others, are reproduced in the context of play or fantasy, and lastly, non-linguistic gesture, where an action communicates an intention through resemblance. The contents of mimetic acts are observable by others, which makes them a potential basis for a culturally accepted mimetic vernacular, enabling members of a group to share knowledge, feelings, customs, skills, and goals, and to create group displays of emotions and intentions that are conventional and deliberate. These types of shared representations seem quite limited, when compared to language, but constitute a powerful means of creating culture and sharing custom, feeling, and intent.

The social hypothesis for language origins is based on the claim that primates use social grooming to bond social groups, and the time available for grooming has an upper limit due to the demands of foraging and food processing. The grooming time is a linear function of group size in both primates and birds so it sets an upper limit to the size of community that can be integrated using the conventional primate mechanism. One of the researchers suggested that language represented a phase shift in communication that allowed this particular glass ceiling to be breached, making it possible for hominins to evolve significantly larger groups than those found among primates. Another researcher showed that the vocal repertoire of the chickadee becomes structurally more complex as group size increases. These findings suggest that the vocal repertoire can become more complex in order to provide a supplementary mechanism for social bonding. The correlation between brain size and group size in primates implies that the first stage of vocal complexity must have occurred with the appearance of the genus Homo around 2 million years ago. The putative demands of instruction in tool manufacture would imply that full-blown language would have evolved at this stage, whereas the social hypothesis requires only an extension of natural primate vocal communication with full grammatical language evolving later.

This article shows the role of ornaments in understanding the evolution of the modern language. The analysis of a geospatial database recording the occurrence of 157 bead types at ninety-eight Aurignacian sites has identified a definite cline in ornament types, sweeping counter-clockwise from the Northern Plains to the Eastern Alps, via Western and Southern Europe, through fourteen geographically cohesive sets of sites. The sets most distant from each other do not share any bead types but share personal ornament types with intermediate sets. Beadwork represents a technology specific to humans, which signals their ability to project social information to members of the same or neighboring groups by means of a shared symbolic language. Symbols applied to the physical body ascribe collectively-defined social status to the wearers that can be understood by the other members of the group only if the latter share the complex codes that establish a link between the worn items, the place and way they are displayed on the body, the social categorization they signal, and the symbolic meaning carried by the objects. The presence of personal ornaments at late Neanderthal sites has been variously interpreted as the consequence of acculturation of local Neanderthals by incoming Aurignacians, as independent cultural evolution of Neanderthals before the spread of the Aurignacian, or as cross-cultural fertilization of late Neanderthals and Aurignacian Moderns.

This article explains role of statistical learning in understanding language development and the interaction between human learning mechanisms and human languages. Infants' statistical learning abilities were first investigated to understand the mechanisms used to segment words from fluent speech, an important first step in acquiring new words. Studies of the connection between statistical learning and lexical acquisition examined regularities in adjacent elements. Statistical learning must be capable of additional levels of analysis if it is a significant component of syntactic development. Recent investigations demonstrate that human learners are not limited to simple adjacent probabilities, but seem to track the types of patterns necessary to exploit distributional cues to syntactic structures. Studies of statistical learning of syntax indicate that the powerful learning capacities include important constraints that help to address the problem of the potentially overburdened distributional learner. The constraints or biases also appear to act on non- linguistic input such as computer alert sounds, and visual nonsense shapes. The constraints that are highly suited to discovering linguistic structure may not be specific to language, but general characteristics of human learning. Statistical learning accounts of language acquisition present an alternative to the traditional innate universal grammar explanation for syntactic acquisition and for the similarities in organization across the world's languages.

This article explores the putting the baby down (PTBD) hypothesis. The hypothesis states that vocal interactions between early hominin mothers and infants resulted in a sequence of events that led, eventually, to the ancestors' earliest words and, later, to the emergence of protolanguage. The modern motherese is more melodic, slower and more repetitious, has a higher overall pitch, uses a simpler vocabulary, and includes special words, as compared to adult-directed speech. Contemporary motherese is known for its musical quality, or prosody. Prosody provides the melody or tone-of-voice in adult speech, coloring it with nuance and revealing emotions. Motherese, as defined in the PTBD hypothesis, is verbal and also covers facial expressions, body language, touching, patting, caressing, and even laughter and tickling. The clarity of motherese that normal babies are exposed to is associated with their development of speech discrimination skills, and infants who are best at perceiving speech sounds at seven months of age score higher when they are older on language tests measuring the number of words they can say and the complexity of their speech. The studies on French- and English-speaking parents and their one- to two-year- old infants show that the extent to which parents incessantly label objects and encourage repetition of names is associated with their babies' vocabulary growth, as well as their ability to manipulate and categorize objects.

This article presents the multiple uses of the concepts of innate and instinctive, by biologists. A broad notion of innate in the sense of having some genetic basis has thus been central to evolutionary approaches to behavior. Lorenz and other ethologists focused on the study of instinct for three practical reasons that include the fact that it justified the discussion and experimental investigation of the adaptive function of behavior, in a Darwinian context, and it allowed ethologists to construct phylogenetic taxonomies of behavior, and thus to explore the evolution of behavior using a comparative method. It signaled a research strategy focused on those aspects of behavior that appear reliably in a species by the time of study, but which avoided the difficult problem of their developmental origins. The developmental psychologist Daniel Lehrman noted that ethologists used the term instinct in multiple different ways. Lorenz and his colleague Niko Tinbergen argued that evolved innate mechanisms could not be avoided in understanding behavior, but that developmental, mechanistic, and evolutionary questions all have a role to play in ethology. Lorenz concluded that learning is impossible without inherited information, but he denied the opposite claim, which was that all instincts entail learning.

The article addresses the issues related to hominins that first embarked upon the language evolutionary trajectory and modality gestural or vocal, used by them. Comparative studies of animal behavior can shed light on these issues provided they follow proper scientific methods. The earliest probable hominin that is well represented in the fossil record, Ardipithecus ramidus (dating to about 4.4 mya), was clearly substantially different from the bonobo, the chimpanzee, or any other primate, at least with respect to locomotor and dental anatomy. Parsimony dictates that any trait present in all descendants of a common ancestor is more likely to have been present in that ancestor than to have evolved separately in each descendant species. In practice, however, a volume of this nature cannot provide an exhaustive survey of the entire animal kingdom. The first article in this section reviews the ape language. It concludes that human-reared and/or trained members of each of the great ape species such as orangutan, chimpanzee, bonobo, and gorilla, have learned to use gestures, tokens, or visual lexigrams. In sum, although non-human primates have often been considered the most intelligent animals, it now appears that many animals are quite smart, and some may rival apes in their language-learning capacities. To date, however, no animal has demonstrated the full range of ape cognitive capacities, and none stands out as a better animal model for language evolution.

This article debates the issues surrounding language or protolanguage and reviews the age-old idea of ape language. Collectively, the studies of the language capacities of the great apes exceed in numbers those of other animals. No matter how sophisticated the cognitive and communicative capacities of other animals may ultimately prove to be, comparative studies of closest phylogenetic kin will continue to provide the strongest evidence of the probable behavioral capacities of the last common ape ancestor, and, hence, of the probable capacities of the earliest hominins. From their inception, ape-language studies have been embroiled in controversies. To some extent, these controversies reflect the differing perspectives of those who hold Darwinian views of continuity between ape and animal minds versus those who adhere to Cartesian traditions of sharp qualitative mental differences between humans and other animals. This review simply describes actual ape behaviors without prejudging their linguistic nature. It does conclude, however, that a number of apes mastered essential components of protolanguage, but none constructed hierarchically structured sentences containing embedded phrases or clauses. This article articulately describes some real-life incidents. Many apes have lived in human homes and/or are trained for various aspects of the entertainment industry. Often, human owners have been convinced these apes understood modern languages. Rarely have these reports been confirmed or negated. A detailed analysis and records of the development of protolanguages concludes this article.

This article reviews recent evidence for advanced, language-pertinent, cognitive capacities in birds and mammals and evaluates the potential suitability of song and other animal vocal behaviors as models for the evolution of speech. Dolphins are extremely vocal, exhibit intelligence across a number of behavioral domains, are highly social, and often cooperate to herd schools of fish. Dolphins can also recognize themselves in mirrors, coordinate body postures and swimming patterns with those of other dolphins, and imitate each other's vocalizations, including unique signature whistles which serve for individual recognition among adults and in the mother-infant dyad. The only other non-primate mammals whose language capacities appear to have been investigated are domestic dogs. Some have also claimed that domestic dogs equal or exceed great apes in social intelligence. It is reported that both elephants and spotted hyenas are unusually intelligent. Elephants remember and recognize by olfactory and visual means numerous conspecifics and classify them into social groups. They also sometimes cooperate to achieve joint goals and seem to understand others' intentions and emotions. Elephants have highly manipulative trunks, use tools for varied purposes, may recognize themselves in mirrors, and may have a stronger numerical sense than non-human primates. They have elaborate vocal, olfactory, tactile, and gestural communication systems and can imitate some sounds.

This article focuses on the evolution of language along with its anatomy, genetics, and neurology. The concepts of instinct and innateness are actually quite useful for describing behaviors that routinely characterize all members of species or at least all species members of specific sex and age classes. Thus, they tend to be favored by scientists with a primary focus on the distinctive behaviors of individual species. To many developmental biologists and developmental psychologists, however, instinct and innateness are fallacious concepts because all behaviors develop through gene-environment interactions. The solution to this dilemma, in Fitch's view, is to abandon the terms instinct and learning in favor of other terms that more accurately describe the phenomena in question, such as species-specific or species-typical to describe behaviors routinely displayed by all members of a species, and canalization to explain the species-typical gene- environment interactions that produce behavioral regularities. From this perspective, language is a species-specific human behavior that is developmentally canalized via interactions of genes and predictable environmental impacts such as typical adult-infant interactions. In sum, evidence indicates that language evolution probably demanded changes in multiple interacting genes and involved expansions in multiple parts of the brain, as well as changes in the vocal tract and thoracic spinal cord.

This article gives an overview on the various brain structures, other than neocortex, contributing to speech and language. The regions of the avian brain which are considered functionally homologous to human neocortex, are nuclear, as opposed to cortical, in their cellular arrangements. The functional significance of nuclear versus cortical neuronal arrangements remains unknown. The intelligence is best measured by ratios that explicitly and/or implicitly discount other neural areas. The most extreme such measure is Dunbar's neocortical ratio that is the ratio of the size of the neocortex to the size of the entire remainder of the brain. The ratio, which is based on the explicit assumption that the neocortex is the primary seat of intelligence, also rests on the implicit assumption that enlargement of non-neocortical brain structures lowers intelligence. The nuclei and basal ganglia contain neurons that are arranged in a non-layered fashion. Such structures may also lie entirely within the brain, and thus have no visible representation on the outer brain surface. The cerebellar lesions can be associated with a much wider range of cognitive and sensory defects, including defects in working memory, procedural learning, syntax, word order, word choice, and autism. The deficits in both the basal ganglia and the cerebellum accompany the orofacial dyspraxia that results from FOXP2 mutations.

This article focuses on the evolution of language over the years. The evidence for primate and human evolution has derived primarily from comparative anatomy and fossil records, although since the 1960s, molecular and biochemical evidences have increasingly been used to delineate phylogenetic relationships among living species and diverse human populations. One of the current research frontiers involves analyses of the DNA of Neanderthals and other fossils. These molecular findings are reviewed by Cann who reports that mitochondrial DNA and the fossil record roughly agree that the phylogenetic split between hominins and panins. It is the earliest possible date for the emergence of protolanguage. Most interpretations of nuclear and mitochondrial DNA suggest that Neanderthal and modern human lineages split somewhere between 270 and 480 thousand years ago (kya), and all modern humans shared a common maternal ancestor in Africa approximately 200 kya. Some mitochondrial DNA data not reviewed by Cann indicates a genetic split between the South African Khoisan peoples and other Africans sometime earlier than 90 kya. The recent nuclear DNA analyses strongly indicate that genetic interchange did occur between modern humans and Neanderthal populations, either directly or indirectly, and, thus, appear to negate completely the strongest versions of the Out-of-Africa model.

Human tool-dependent foraging strategies enable humans to exploit a much wider range of environments, live in larger social groups at increased population densities, reproduce at shorter intervals, and have expanded lifespans and brain size. Language is integral to human tool-dependent foraging. Humans share information about locations of natural resources needed to make tools and about the physical properties and appropriate treatment of technical materials. Foragers also share information acquired during hunting and gathering expeditions. Hominin ancestors embarked upon new non-ape-like foraging strategies by at least 2.63 mya. This included crushing bones to obtain marrow, using sharp-edged stone flakes to cut meat from bones, and, possibly, exploiting underground plant storage organs. Hominins began using fire to cook, and containers to gather and transport food to home bases at some point. They also mastered new social foraging strategies, including male-female food-sharing bonds, and parental and grandparental provisioning of the young. Hominins were using spears and hunting big game by 400 kya. Modern humans were charting lunar cycles and predicting tidal fluctuations by 164 kya, in South Africa, in order to improve the efficiency and safety of shellfish collection. Europeans were predicting and exploiting seasonal migrations of fish and mammals by upper palaeolithic times.

This article focuses on two roles of gesture and explores the changes that take place in the manual modality when it is employed to fulfill the functions of language on its own. Gestures reflect a global-synthetic image. Gesture is idiosyncratic and constructed at the moment of speaking and it does not belong to a conventional code. The gesture conveys nuances of the coastline that are difficult to capture in speech. Gesture allows speakers to convey thoughts that may not easily fit into the categorical system, which are offered by conventional language. The gestures that accompany speech are not composed of parts but instead have parts that derive from wholes that are represented by way of imagery. The imagistic base of gesture allows it to capture and reveal information that speakers may have difficulty expressing in speech. Gesture can also play a role in cognitive growth by providing an imagistic route through which ideas can be made active or brought into the learner's repertoire. The manual modality assumes an imagistic form when it is used in conjunction with a segmented and combinatorial system. Modern-day human communication systems are based on a segmented and combinatorial mode of representation that gives the system its generative capacity. The gestures that speakers produce in the manual modality can express information that they are often not able to express within the codified spoken system. This information is processed by the listener and becomes part of the conversation.

The adaptive success of organisms depends on the categorization that is the ability to do the right thing with the right kind of thing. Most species can learn categories by direct experience (induction) and only human beings can acquire categories by word of mouth (instruction). Language began when purposive miming became conventionalized into arbitrary sequences of shared category names describing and defining new categories via propositions. An individual must be able to distinguish the members from the non-members in order to categorize correctly. The feature detector for some categories is inborn. Most categories, however, have to be learned through trial and error during the lifetime of the organism. The artificial-life simulations have showed that simple virtual creatures in virtual worlds, which must learn to do the right thing with the right kind of thing in order to survive and reproduce, are able to categorize through trial-and-error experience. It can be done with the help of neural nets that are able to learn to detect the features, which reliably distinguish one category from another.

This article aims to focus on the studies of grammaticalization that can be applied for reconstructing earlier phases in the evolution of language. Grammaticalization theory offers a tool for pushing linguistic reconstruction back to earlier phases of linguistic evolution, that is, to phases where human language or languages can be assumed to be different in structure from today's languages. Grammaticalization is defined as a process involving the development from lexical to grammatical forms, and from grammatical to even more grammatical forms and constructions. The assumptions and observations underlying the methodology of grammaticalization theory include development from early language to modern languages involved linguistic change, in which an important force driving linguistic change is creativity. Linguistic forms and structures have not necessarily been designed for the functions they currently serve. The grammaticalization of demonstratives shows that functional categories may change in such a way that they bear little resemblance to their original design. The first step in this process is from demonstrative to definite article and subsequently the element may develop further to be used for indefinite reference, and in a final stage the demonstrative may turn into a semantically largely empty marker of nominalization. Grammatical forms such as case, agreement, and voice markers are regarded as the result of gradual evolution, so that the earliest stage of human language that is reconstructable by the methodology of grammaticalization theory must have lacked grammatical categories such as case, agreement, and voice.

This article reviews several studies on the behavioral and neuroanatomical asymmetries in non-human primates pertaining to the production of communicative behaviors. Hopkins and his team have reported population-level right-handedness for interspecies manual gestures associated with the request for food from a human. Meguerditchian and co-workers examined handedness for a variety of manual gestures during inter and intra-species communication in captive chimpanzees and found that the apes were significantly right-handed for all gesture types. Hauser reported that the left side of the face began to display facial expressions earlier than the right side for open-mouth threat and fear grimace in rhesus monkeys. Hauser and Akre examined the onset of mouth-opening asymmetries in rhesus monkeys during the production of several types of vocalizations. Hook-Costigan and Rogers showed that common marmosets displayed a larger left hemi-mouth during the production of fear expressions, including those that were or were not accompanied by a vocalization. Fernandez-Carriba with co-workers reported significant left orofacial asymmetries for several facial expressions including hooting, plays, silent-bared teeth, and scream face. Losin's team assessed orofacial asymmetries for four facial expressions associated with vocalizations in chimpanzees including hooting, food-barks, extended food grunts, and raspberries. Losin has found that food-barks and hoots were expressed more intensely on the left side of the face whereas extended food grunts and raspberries were expressed more intensely on the right side.

Researches in language evolution have presented some continuity between apes and humans. Researchers have shown that precursors to both sentence meaning (conceptual meaning) and speaker meaning (pragmatic meaning) are present in animals. They have also reported that something other than the ability to comprehend such meanings was necessary to launch language, perhaps shared intentions, and once language was launched it resulted in abilities to create new kinds of meanings. A phenomenon extensively researched in both developmental and comparative psychology is object permanence. There are two forms of the object permanence test, one harder than the other. The easier test, the visible object permanence test, involves simply moving an object, such as a treat, behind a screen, where it is invisible to the animal or child subject, restraining the subject briefly, and then seeing if the subject moves to retrieve the object from behind the screen. The harder test, the invisible object permanence test, involves placing the treat into a small container in view of the subject, then the container is hidden behind the screen, where it is emptied out unseen by the subject and the empty container is then shown to the subject, who passes the test if he/she searches behind the screen. The episodic memory is related to object permanence. This is a kind of memory for specific events that have happened to the individual subject.

This article gives an account of vocal communication and cognition in cetaceans that comprise aquatic mammals. Cetacean communication occurs primarily in the acoustic domain. Light scattering and absorption leads to very limited visibility underwater while the sense of olfaction is virtually absent. The males of most baleen whale species produce long, elaborate song sequences during the breeding season. These appear to keep other males away and attract females. The song of the humpback whale has a hierarchical structure and is the most complex one among whale songs. It consists of phrases that are made up of multiple elements. The patterns of change in the song of humpback whales demonstrate clearly that these animals are capable of vocal learning, a relatively uncommon trait in mammals. All males in a population sing the same song at any one time, but the song of the population changes over the singing season. The bowhead whale has a simpler song but changes song in synchrony similarly to humpback whales. The songs of other baleen whales are much simpler and often consist of only one to three elements that are repeated in long song sequences. Bottlenose dolphins and several other dolphin species produce individually distinctive signature whistles that develop early in life. These can remain stable for at least a decade and, in the case of females, most likely for their entire lives. Signature whistle development is influenced by vocal learning, with dolphins copying and modifying aspects of other animals' whistles to develop their own unique frequency modulation pattern.

This article investigates approaches adopted to explain the role of cultural transmission in linguistic structure. One of the approaches is to build working models of populations made up of individuals that interact and acquire language from each other, which uncovers the general relationship between learning biases/constraints and emergent language universals. There are three broad approaches to this kind of modeling that include computational/robotic, mathematical, and experimental approaches. There are a number of ways these models could be configured, but the iterated learning model (ILM) provides a framework, which characterizes many of them. The guiding principles for the ILM include that individuals are explicitly modeled, individuals learn by observing instances of behavior, and individuals also produce behavior as a result of learning that then goes on to be input to other individuals' learning. Researchers used a mathematical model of learning placed within the iterated learning framework to try and answer precisely how the nature of the learner impacts on the structure of language. A recent emerging trend is the use of experimental techniques with human participants to build close analogues to the computational and mathematical models of iterated learning in the laboratory. The technique offers several advantages such as it can be used to test the generality of conclusions from models in a situation where the prior bias is provided by real human biology. It can be used to analyze whether results such as the emergence of compositionality from a holistic protolanguage can really occur in a feasible timescale.

This article examines the social conditions for the evolutionary emergence of language. Human psychology evolved in adaptation to a particular way of life, based on hunting and gathering. Evolving humans compensated for vulnerability to dangerous predators by developing unprecedented forms of social cooperation, material culture, and strategies for remembering, transmitting, and exchanging accumulated knowledge. One of the views known as deep social mind holds that distinctively human forms of cultural transmission necessarily co-evolved with cooperative mindreading together with increasing egalitarianism. Humans everywhere may share dispositions toward dominance as a part of the inherited psychological package but equally, humans have corresponding tendencies to resist being dominated. At a certain point in human evolution, the benefits of deploying Machiavellian intelligence to impose dominance over others became matched by the costs of overcoming the Machiavellian resistance of others. The increased human group sizes placed a premium on enhanced social intelligence, the ability to negotiate alliances, in turn driving selection pressures for neocortical expansion. Human hypersociality and intersubjectivity emerged initially under such selection pressures, with mothers increasingly willing to trust allocarers with their babies.

This article explains the emergence of the language faculty over the years. The organisms are complex and integrated so any adaptive change must automatically spin off structural by-products. Some properties are not selected for and are not accidental by-products, but they emerge because of deep, physical principles that affect much of life. They reflect limits on the kinds of things that evolution can make, and they arise through the interaction of physical principles. Physical laws describe the limits to evolutionary change, in the same way that principles of universal grammar (UG) prescribe the limits to grammatical change at the phenotypical level. The multifaceted approach to the evolution of the language faculty differs from the approach of people whom Gould called singularists. Singularists invoke just one factor to explain evolutionary development that is natural selection. The result of natural selection is adaptation, the shaping of an organism's form, function, and behavior to achieve enhanced reproductive success. Singularists suggest that selective forces shaped individual components of UG, such as the Subjacency Condition, which permits elements to move only locally. Modern Panglossians show that the Subjacency Condition constrains speakers to produce forms that can be understood in accordance with an individual's apparent parsing capacity.

This article presents several factors related to the evolution of vocal and phonetic behaviors thus discussing the emergence of symbolization and reference. Evolutionary theories must identify the environmental changes that produced phenotypic variation and the modes of selection that reinforced certain of the variants, thereby increasing reproductive success, and they must specify the developmental stages in which these actions took place. The primary task of evolutionary theorists is to identify the environmental changes, and the responses to those changes, that edged our ancestors closer to the linguistic capacity possessed by modern humans. A new paradigm, evolutionary developmental linguistics (EDL), a naturalization of human language, is concerned with the evolution of developmental properties, processes, and stages that independently, or in concert with other environmental changes, facilitated the emergence of language in the species. Modern humans have four developmental stages that include infancy, childhood, juvenility, and adolescence. Much of the linguistically relevant phenotypic variation originated in ancestral infancies, with selection by parents occurring in this stage, and, with persistence of selected behaviors, in later stages by peers and others. Juvenility provides additional time for the brain growth and learning required for reproductive success in various species of mammals. The modification of juvenility would naturally increase phenotypic variability and offer new bases for selection at a time when greater independence and sexual maturity were rapidly approaching.

This article provides details on human speech production involving a range of physical features, which may have evolved as specific adaptations for this purpose. All mammalian vocalizations are produced similarly, involving features that primarily evolved for respiration or ingestion. Sounds are produced using the flow of air inhaled through the nose or mouth, or expelled from the lungs. Unvoiced sounds are produced without the involvement of the vocal folds of the larynx. Mammalian vocalizations require coordination of the articulation of the supralaryngeal vocal tract with the flow of air, in or out. An extensive series of harmonics above a fundamental frequency, F0 for phonated sounds is produced by resonance. These series are filtered by the shape and size of the vocal tract, resulting in the retention of some parts of the series, and diminution or deletion of others, in the emitted vocalization. Human sound sequences are also much more rapid than those of non-human primates, except for very simple sequences such as repetitive trills or quavers. Human vocal tract articulation is much faster, and humans are able to produce multiple sounds on a single breath movement, inhalation or exhalation. The unique form of the tongue within the vocal tract in humans is considered to be a key factor in the speech-related flexibility of supralaryngeal vocal tract.

This article focuses on the evolution of phonology over the years. The most comprehensive investigation of the innateness hypothesis in phonology is that undertaken by Mielke regarding the common claim that there is a small finite set of universal innate distinctive features that can describe the sound patterns participating in what are called phonological processes of all languages. He points out that the multiple sounds often participate in the same sound pattern. When a group of these sounds exhibits the same behavior it is often the case that these sounds are phonetically similar to each other. This type of grouping of sounds is termed a natural class. Syllabic sonority is considered to be an innate mental principle revealed by the fact that the loudest sound in a syllable is the vowel, and sonority then tends to decrease as the distance from the vowel of a preceding or a following consonant in the same syllable increases. The pattern can be attributable to peripheral biomechanics rather than mental structure. The concept of markedness is considered to involve another innate mental principle. The discipline of phonology has contributed an enormous amount of valuable information about the sound patterns of language.

This article focuses on the evolution of Homo and presents the origins of humanness. The earliest fossils assigned to the genus Homo come from Kenya, Ethiopia, Tanzania, and South Africa and are currently classified as Homo erectus. African Homo erectus fossils, the earliest dated to about 1.8 mya, include cranial, dental, and postcranial specimens, and the almost complete skeleton of an adolescent. Homo ergaster, a species distinct from the later-in- time Homo erectus fossil samples from Asia, has been proposed to accommodate early African fossils such as KNM-ER 3733. The increased brain size dramatically influenced cranial architecture during the course of human evolution. Skulls of later members of the genus Homo have an increasingly high and globular shape, with the maximum width of the skull, low and approximately at the level of the external ear canals as earlier described for Homo erectus, gradually moving higher on the vault, producing the strongly marked eminences on the parietal bones of modern humans. The development of stone tools allowed early Homo to exploit a greater range of habitats, eventually resulting in an expansion into Eurasia. The Dmanisi evidence includes at least four skulls, one with an associated mandible as well as other cranial and dental specimens, and stone tools similar to the Oldowan tools from East Africa. These fossils have some features similar to those of African Homo erectus and some similar to the transitional species Homo habilis.

This article provides an overview on two human universal features, music and language, which can be vocal, gestural, and written down. Both are hierarchically structured, being constituted by acoustic elements (words or tones) that are combined into phrases (utterances or melodies), which can be further combined to make language or musical events. The languages and musical styles can be described as forming families within which patterns of descent, blending, and development can be reconstructed. Communication with babies and infants has a particularly high degree of musicality. This is known as infant- directed speech (IDS) or motherese. The key characteristics of IDS are the extended articulation of vowels, heightened pitch, and exaggerated pitch contours. Several researches has shown that these are not simply used to facilitate the acquisition of language by infants but the musicality of speech has its own function in terms of its emotional impact on the infant. The infantile musical capacities could be a spin-off from language acquisition and the musicality of IDS is considered to be critical to the acquisition of language. The studies of those suffering from brain damage or congenital conditions show that music and language have significant degrees of independence in the brain, even a double dissociation.

This article presents the principles of linguistic geography and palaeodemography, which indicate that language originated gradually over a diverse population of pre-languages and pre-language families. Many linguists discussing the origin of language assume there was a single origin of language and therefore a single ancestral language, a Proto-World, whether or not reconstructable from modern data. The cognitive capacity for symbolic behavior and complex knowledge is likely to have been present in modern humans from the very beginning, but its manifestation in actual transmitted behavior must have depended on population size. Ergativity is the identical coding of subject of intransitive verb and object of transitive verb, with subject of transitive verb differently marked. Languages with ergative case paradigms of nouns include Basque, Georgian, and Chukchi. A singularity is a linguistic phenomenon well attested only in one area or family on earth. Singularities show that highly unusual grammatical properties are hard to innovate, yet hence easier to acquire by diffusion or inheritance than by innovation. One of the examples of a singularity is, click, which are robustly attested in all three of the endemic language families of southern Africa and also well installed in some of the intrusive Bantu languages. They are also found as outliers in two language isolates of the southern Horn of Africa and one Cushitic language there, and the usual interpretation is that these survive from a once larger click-using area that has now been mostly overrun in the Bantu expansion of some 3000 years ago.

The combination of in-depth molecular anthropological analyses and linguistic investigations exhibits some of the factors involved in the prehistoric language contact. The two parts of the human genome that are studied most widely in molecular anthropology, due to their very specific mode of inheritance, include mitochondrial DNA (mtDNA) and the Y-chromosome. MtDNA is a small circular molecule that exists in large copy numbers in special little organelles in the cell called mitochondria. Its special advantage in molecular anthropological studies lies in the fact that it is inherited solely in the maternal line. The Y-chromosome, on the other hand, is one of two sex chromosomes found in the human genome, with the X-chromosome being its counterpart. Molecular anthropological analyses can provide indications of prehistoric admixture events, sex-biased migration patterns, decreases or increases of population size, and settlement practices. These results allow insights into prehistoric sociocultural practices that may have had an effect on language change in contact situations. The detection of prehistoric language shift is significantly important in the study of language contact. The language shift can result in a mismatch between the genetic and linguistic affiliation of a group, which can be detected with genetic methods. The linguistic investigations of languages, which can be shown genetically to have been the target of a language shift, can provide evidence for what linguistic changes, if any, such a shift produces.

Most language evolution research focuses on primates, positing a hominin transitional link with emerging learned vocal communication. Such research increased after apes, humans' closest genetic relatives, learned elements of human communication systems. This article traces the evolution of language and communication with special reference to parrots and other songbirds. Grey parrots, despite considerable phylogenetic separation from humans, acquire comparable human-like communication skills and, unlike present-day apes, can imitate human speech because they can learn novel vocalizations. Specifically, they acquire species-specific and heterospecific vocalizations by actively matching their progressive production of specific sound patterns to live interacting models or memorized templates. Research on selective pressures resulting in avian vocal learning and imitation could provide clues about pressures leading to similar human skills. To understand the ancestral hominin condition, language evolution researchers might use models based on both phylogenetic kin and birds. Birds, although having diverged from the lineage leading to humans approximately 280 million years ago, can provide models for the evolution of vocal communication.

The properties of modern instances of language creation offer significant details on several aspects of language evolution. A pidgin is the linguistic creation of a new contact community that has need for a medium of interethnic communication (MIC) for specific purposes but does not share a pre-existing language that can fulfill this function. Pidgins represent dynamic phenomena that show qualitatively different developmental stages, ranging from unsystematic, ad hoc jargons, to more systematic but still highly restricted MIC displaying structural norms, and to more elaborated MIC that come to be used in a variety of functions in a complex multilingual society. The critical steps in the evolution of grammar cover a progression from one-word, mono-propositional communication, to the appearance of protogrammar and multi-propositional discourse, and then to the integration of protogrammar into the more 'arbitrary' encoding of the emergent grammatical mode. Jargons, which are often indiscriminately lumped together with pidgins, are aggregates of individual solutions to the problem of interethnic communication. They are characterized by a high degree of variability, transfer from languages known to the speakers, feature stripping, and a lack of linguistic norms. The transition from jargon to stable pidgin coincides with the formation of a language community and the emergence of socially accepted norms, which occurs when none of the languages in a heterogeneous milieu serves as a target language.

This article describes the primate social cognition as a precursor to language. The goal of phylogenetic reconstruction is to group similar animals together. One method of phylogenetic reconstruction is based on measures of distance, and arranges species into a phylogeny such that each is grouped with those with which it shares the greatest number of characters. Other methods rely on parsimony, generating the phylogeny that requires the fewest evolutionary changes in character states. Among primates, both methods yield a branching tree structure in which humans are grouped more closely with apes, less closely with Old World monkeys, and progressively less closely with New World monkeys, prosimians, and non-primate mammals. This phylogeny is consistent with both distance and parsimony such as morphological and genetic evidence to indicate both that there is less-evolutionary distance between humans and chimpanzees/bonobos than between humans and any other primate and also that a phylogeny that groups humans and chimpanzees/bonobos together is more parsimonious than a phylogeny that does not. Non-human primates use acoustically different vocalizations in different social contexts, suggesting that the mechanisms underlying call usage have a strong genetic component, although perhaps not as strong as the mechanisms underlying call production. The theory of mind spurred individuals not only to recognize other individuals' goals, intentions, and even knowledge as monkeys and apes already do but also to share their own goals, intentions, and knowledge with others. The evolution of a theory of mind thus spurred the evolution of words, grammar, and the vocal modifiability that these traits required.

This article provides an overview of bird song and language. There are several reasons why bird song might be of interest to those who are studying human language. First, and most obviously, it is a system of communication. Birds use sounds to communicate with one another. The most elaborate sounds are referred to as songs; males largely use songs in the breeding season to attract mates and keep rivals out of their territories. But there are other simpler sounds, usually labeled as calls, which fulfill other functions and are often used by both sexes throughout the year. Sounds can go round corners and are as useful by night as they are by day, both features that give them an advantage over visual signals. The third main modality, that of smell, has the advantage of persistence, as when the scent marks of one dog are sensed by another days later, but is certainly not appropriate for the transfer of a complex and changing stream of information. Beyond these two basic similarities comes a fourth, superficially more important, one: birds, like human beings, often have a huge repertoire of different sounds. To conclude, it is clear that vocal communication is of prime importance in many birds as it is in humans. Some of the similarities, such as that between our vocabulary and the large song repertoires found in many birds, are superficial. But the fact that learning plays a role in the song development of many birds, as it does in language development, may help us to look back in time and think about the reasons why this crucial evolutionary step took place on the way of language development.

This article raises an important question that asks whether the vocal capacities of great apes have been underestimated or not. Considerable research effort has been dedicated to vocal communication in primates, and has revealed communicative and cognitive traits in non-human primates that have relevance for language evolution. The vast majority of vocal communication studies to date have, however, focused on monkey species. In contrast to both research into monkey vocal communication and research on other aspects of great ape behavior and great ape vocalizations has been surprisingly limited. This relative paucity of information on great ape vocal behavior has serious consequences for the understanding of language evolution. First, given that apes outperform monkeys on many cognitive tasks, further research on great apes may reveal that they use their vocalizations in a more sophisticated way than monkeys, possibly demonstrating more commonalities with humans. This article refers to mammals such as chimpanzees and orangutan. Chimpanzee barks are also produced in a context-specific manner, indicating they have the potential to function referentially. Crockford and Boesch found that wild adult male chimpanzees produced bark variants in response to snakes, and whilst hunting. These barks were sometimes combined with other calls or drumming and when produced in conjunction with other signals, they were highly context specific. Playback experiments are now required to assess whether recipients extract meaningful information from these context-specific calls. Many issues need resolving, and numerous areas require more systematic investigation. In particular, the issue of the degree of volition and intentionality that drives call production in great apes must be addressed, as this currently represents a chasm between human and non-human primate vocal communication.

This article provides an overview on the contributions of formal models in the evolution of language and addresses some common criticisms of formal models. A formal model is any description of a system that is sufficiently precise that predictions about the behavior of that system can be more or less mechanically produced from that description. Two types of formal model are commonly used that include mathematical and computational models. Predictions can be mechanically derived from the detailed specification of the model. One of the best-known formal models in evolutionary linguistics is Kirby's model of the cultural evolution of recursive compositionality. The model explores the theory that cultural transmission can produce a structured language from an initially unstructured, holistic protolanguage, through a historical process of cumulative fractionation. Kirby's computational model shows that, under certain assumptions, a recursively compositional language can indeed evolve from a non- compositional predecessor through purely cultural processes. A simple model includes only the minimal set of assumptions required to test the relevant aspects of the theory and abstracts away from everything else such as a recent tendency in part of the formal modeling literature has seen the replacement of relatively complex models with much simpler, much more abstract models. Recently modelers are testing the assumptions and predictions of their models on real human beings, in laboratory experiments. One of the approaches is to test the predictions of models directly in laboratory populations.

The human hands, face, and vocal machinery have evolved as finely differentiated parts as compared to other primates due to the two phenomena that includes child development and computational modeling. Infants imitate face and hand action as well as speech. All three modalities may share a common evolutionary path to organ differentiation through imitation. Facial imitation is unique among the three because infants can neither see the face they feel nor feel the face they see, so that imitation must be mediated by an intermodal representation. Language, spoken or signed, evidently requires an integral anatomical system of discrete, independently activated parts that can be coordinated to effect rapid sequences of expressive global action. Consonants are specified by acoustic trajectories, formed by gestural combinations of varying degrees of complexity. Lindblom's proposed a modified dispersal algorithm to predict consonant-vowel (CV) syllable trajectories by means of a cost/benefit ratio (articulatory cost/perceptual discriminability) summed and minimized over a system of syllable trajectories such as might appear in a small lexicon. Lindblom's work offers the most comprehensive computational model so far available of how systems of discrete gestures, phonemes, and syllables may have emerged by self-organization under perceptuomotor constraints from an evolved vocal tract.

This article explains the evolution of human language and the brain. There are many ways organisms can adapt to moving targets. One of the ways is genetic evolution, when natural selection acts on variation in the population, selecting against those alleles that provide the least fit to the environment. The second way is by utilizing the phenotypic plasticity of a genotype. The third way is by means of systems and organs, which have evolved to cope with fast-changing environments and which have genetic underpinnings also. A set of genes can give rise to different phenotypes depending on the environment in which development takes place. The phenomenon, phenotypic plasticity, may be adaptive in species with variable environments. When natural selection acts to preserve adaptive phenotypes, it can lead to genetic change and to the fixation of specific phenotypes within a population by several evolutionary processes, including the Baldwin effect and genetic assimilation. The human brain is a very specific organ selected for the ability to track fast-changing parts of the relevant environment, which for hominins also included the linguistic environment. The human brain is highly efficient when it comes to language acquisition and production and is more efficient than any other known brain or artificial computing mechanisms.

As the title suggests, this work chronicles the evolution of language with special reference to animals. Most organisms communicate with conspecifics, whether intentionally or not, and such communication encompasses all conceivable mechanisms. Vocal and other sound-based signals, such as clicking wings or legs, are common in animals. Visual signals are also widespread, including those associated with humans and other primates: manual and facial signals, and bodily postures. The volume is divided into five parts. Part I, about insights from comparative animal behavior, examines animal communication systems and cognitive capacities of potential relevance to the evolution of language and speech. Part II, which details the biology of language evolution including anatomy, genetics, and neurology, offers various views of the physical components of a language faculty. Part III is about the prehistory of language, and in particular askes: When and why did language evolve? The text presents current interpretations of the selective events that may have led to the evolution of language. Part IV, is on launching language and looks especially at the development of a linguistic species, and it presents articles dealing with central properties to be accounted for in language evolution, and issues surrounding the forces that shaped the language faculty. Finally, the articles in Part V look at language change, creation, and transmission in modern humans, and this part of the book examines a number of putative windows on language evolution; for instance, modern events involving language emergence or change, for which there exists a reasonably concrete evidence, might shed light on the evolution of language itself.

This article deals with the different views of researchers on the central properties to be accounted for in language evolution. Stephen Anderson presents certain structural regularities become established in the world's languages, including universal properties such as structure dependence. Anderson argues that there is no need to assume a dichotomy between a genetically determined language faculty and a language faculty shaped by external factors, such as functional pressures and the effects of grammaticalization. The language faculty supports the learning of specific kinds of linguistic systems, and it would not be at all surprising if natural selection favored those who were able to acquire language most efficiently. Grammars that are most easily learned will be the ones that are acquired, because generations of better learners also shaped grammars to be more learnable. James Hurford, Michael Corballis, Stevan Harnad, Terrence Deacon, and Robbins Burling investigate what cognitive capacities must have evolved before the evolution of any kind of language. These capacities include the development of meaning (semantics and pragmatics), the origins of grounded symbols, and the ability to learn and store words. Hurford argues that other animals possess at least proto-conceptual categories, which form the basis for conceptual meaning. Animals exhibit planning abilities, have mental representations of territory, and can make calculations based on their knowledge, such as transitive inference.

This article discusses the kinds of universal syntactic capacities that prompt many linguists to postulate that syntax is a separate, biologically determined entity. Lexical items are stored in the mental lexicon, an inventory of arbitrary form-meaning associations. These include single words and morphemes smaller than words (such as affixes), multi-word idioms, set phrases, and constructions of various kinds. Vocabulary learning in humans is sophisticated, involving a complex mix of grammatical properties, phonology, semantics, and cultural knowledge. Some aspects are universal, others language-specific. Vocabulary items belong to complex, structured semantic categories. Universally, verbs fit into one or more subcategorization frames, which specify the number and type of obligatory dependents of the verb. The human lexicon displays at least three further unique characteristics. First, the speakers probably store at least 50,000 entries for each of their native languages. Second, though the learning of syntax, phonology, and morphology is subject to critical period effects, new lexical items are learned throughout life and there is no critical period for vocabulary acquisition. Third, the human lexicon crucially contains two major classes of items that include content words, known as lexical categories, and grammatical elements, or functional categories. The lexical/functional division occurs in all languages, including simple languages, such as Riau Indonesian, although functional categories in particular vary greatly cross-linguistically.

This article discusses the emergence of protolanguage. Several researchers suggest that early hominin communication involved some form of pre-language, or protolanguage. Protolanguage is seen as simpler than full language, with a proto-lexicon. Protolanguage may have utilized vocal, gestural, and mimed components. A compositional or lexical protolanguage consists of single protowords, initially uttered separately and slowly, and subsequently joined in short, fairly random sequences. It has no hierarchical structure, no syntactic combinatorial principles, and only a loose pragmatic relationship between protowords. Protolanguage exhibits several properties. One of the properties is that the ordering of elements is relatively random. No hierarchical syntactic structure constrains surface order, and different word orders have no link to information structure. Ancestral protolanguage putatively contained various purely semantically based principle that map into linear adjacency without using anything syntactic. Ancestral protolanguage putatively lacked a mechanism for assembling words into structural units. The protolanguage lacks a distinction between lexical elements primarily verbs, nouns, adjectives and functional elements such as grammatical items, including determiners, auxiliaries, and sub- words. Modern protolanguages lack grammatical markers, while in full languages, functional and lexical elements occur in roughly equal proportions in utterances. The transition to language involved the gradual accretion of other word classes via the same processes of grammaticalization that occur in all recorded languages.

This article covers the processes of (modern) language creation and change, and the roles played in language evolution by socio/cultural transmission. Bernd Heine and Tania Kuteva report on the uses of well-known processes at work in observable language change to reconstruct a plausible scenario for the development of the earliest languages. Joan Bybee reports on the concept of grammaticalization that refers to a bundle of processes causing diachronic change that are known to occur in all languages. Grammaticalization is posited as a critical driving force in the evolution of language, and grammaticalization theory gives us a scientific tool for reconstructing earlier linguistic states. Paul Roberge argues against the prevailing view concerning the role of child learners in language change in connection with the formation of creoles. He argues that native acquisition of pidgins is not necessary to form creoles, which are full linguistic systems. Roberge compares the factors leading to the evolution of full language from protolanguage with the factors involved in the formation of pidgins and creoles. Susan Goldin-Meadow reports on the theme of language creation. She explores the role of the manual modality when used alongside speech, and then investigates what changes occur when this modality fulfils all the functions of language, without speech. Sign languages are fully- fledged languages, but more primitive gestural communication occurs in homesign systems.

This article highlights gesture as the most flexible modality of primate communication. An understanding of the complex issue of language evolution must be grounded in a range of disciplines, including linguistics, psychology, neuroscience, philosophy, archaeology, and primatology. The evolution of language is typically debated within a hypothetical framework, but we can look to extant non-human primate communication to help shape the discussion. One of the most interesting and least studied forms of social communication in apes is gesture. All four species of great ape that include bonobo, chimpanzee, orangutan, use their hands to communicate, but gestures are difficult to study in the wild. A notable exception is one of the first reports on gestures in wild chimpanzees studied by Goodall. The most detailed studies of gesture historically concerned human-reared individuals trained to use American Sign Language. This article reviews gestures studied in two species of great ape, chimpanzees and bonobos. The gestural origin of language theory offers a tantalizing scenario for what human language may have looked like in its early stages, and this article reviews the data on ape gestures that support this theory, or rather, a suggested modified version.

This article reveals the work carried out on evolutionary biology of language that can proceed in two ways such as through an examination of the fossil record and through comparative primate neuroanatomy. The structures in the peri-Sylvian region of the left hemisphere are necessary for language. These include Broca's area, the parietal-occipital-temporal junction or POT. The lack of a POT is indicated by the existence of a major sulcal division, the lunate sulcus, at the terminus of the Sylvian fissure. The existence of a Broca's area and a POT are considered indicative of a hominin anatomical configuration rather than a great ape configuration. The POT region in modern humans is essential to language and to basic conceptual structures. The anatomical mosaic parts essential to language have not been shown to be homologous to anatomical structures that support vocal communication in related ape species. The spatial structure concepts that are evidently necessarily expressed in some fashion or other in language involve motion and location and are typically represented functionally in terms of source, goal, theme, and location, and involve places and paths. Human cognition and language depend on neuroanatomical structures, which lie adjacent to, and are intimately connected to, portions of the posterior parietal cortex that are responsible for spatial cognition.

This article reviews the fossil evidence for human evolution from the earliest hominins to the emergence of Homo erectus. There are many differences between the hard-tissues of living modern humans and chimps/bonobos. Most researchers agree that the last common ancestor (LCA) of the hominin and panin clades was probably more likely to have been chimp/bonobo-like than modern human-like. The earliest members of the hominin clade would most likely have had smaller canine teeth, larger chewing teeth, and thicker lower jaws as compared to the earliest panins. There would also have been some changes in the skull and postcranial skeleton linked with more time spent upright and with a greater dependence on the hind limbs for bipedal walking. These changes would include a forward shift in the foramen magnum, wider hips, habitually more extended knees, and a narrower, more stable, foot. The group, possible hominins, includes Ardipithecus ramidus, Orrorin tugenensis, Sahelanthropus tchadensis, and Ardipithecus kadabba. The main differences between Ar. Kadabba and Ar. ramidus s. s. (sensu stricto) are that the upper canine crowns of the former have longer crests, and that the P3 crown outline of Ar. kadabba is more asymmetrical, and thus more ape-like, than that of Ar. Ramidus. Another group, archaic hominins, covers two genera, Australopithecus and Kenyanthropus. Australopithecus afarensis is the earliest hominin to have a comprehensive fossil record including a skull, several crania, many lower jaws, and sufficient limb bones to be able to estimate stature and body mass.

This article deals with some of the major developments in hominin technology, subsistence, social behavior, and cognition, which are outlined by the archaeologists of the Paleolithic. One of the innovative technologies, Mode 1 tools, consists of the three basic varieties of stone tool that include hammers, cores, and flakes. The knapper In Mode 1 technology uses a hammer, which is a roundish hard stone, to strike the edge of another stone, termed a core. Hominins used the sharp flakes to butcher carcasses of medium (antelope-sized) and occasionally large (e.g. giraffe) mammals. Hominins also used stone hammers and cores to smash long bones for marrow, and at some Mode 1 sites the presence of stones with crushed surfaces indicates that the hominins were pounding more than just bones possibly also roots or corms, though pounding meat itself would have rendered it easier to digest. Homo erectus produced a new kind of lithic technology that archaeologists term Mode 2 or Acheulean. All of the Mode 1 elements continue in Mode 2, but were augmented by a very different kind of stone tool termed biface. A biface is large stone tool made by trimming the margins of a core or large flake bifacially. Bifacial trimming resulted in two types of tool with sturdy cutting edges around most of their margins that include cleavers with an unmodified bit at one end and handaxes whose sides converged to a narrow tip or point. Fire also appears to have been a component of Homo erectus technology.

Primates communicate not only because they are biologically hardwired to do so, but also because they pursue specific goals during social interactions. This is well documented in the context of ape gestural signals, which have revealed a considerable degree of flexibility in interesting ways. In terms of vocal behavior, however, both monkeys and apes appear to be much less flexible, which raises important questions about how and why vocal flexibility evolved in the human lineage. The emerging picture is that, across the primate order, flexibility is widespread in call comprehension but largely restricted to humans in call production. Non-human primates, including the great apes, are curiously constrained by weak motor control over their vocal apparatus, resulting in limited vocal repertoires. A key transition in the evolutionary origins of language may have been when early humans began to interact with each other collaboratively. Another prediction is that, the species in which infants are exposed to competition over non-maternal caregivers should be more likely to exhibit elaborate vocal behavior than species in which their mothers raise infants only. Research on the communicative skills of other cooperative breeders, particularly communal breeders, may provide interesting empirical data to test this hypothesis.

Language evolution might have preferred certain prior social configurations over others. Experiments conducted with models of different social structures (varying subgroup interactions and the presence of a dominant interlocutor) suggest that having isolated agent groups rather than an interconnected agent is more advantageous for the emergence of a social communication system. Accordingly, distinctive groups that are closely connected by communication yield systems less like natural language than fully isolated groups inhabiting the same world, while the addition of a dominant male who is asymmetrically favoured as a hearer, and equally likely to be a speaker has no positive influence on the quality of the emergent communal language.

The Oxford Handbook of Language Evolution presents critical accounts of every aspect of the field. The book's five parts are devoted to insights from comparative animal behaviour; the biology of language evolution (anatomy, genetics, and neurology); the prehistory of language (when and why did language evolve?); the development of a linguistic species; and language creation, transmission, and change. Research on language evolution has burgeoned over the last three decades. Interdisciplinary activity has produced fundamental advances in the understanding of language evolution and in human and primate evolution more generally. This book presents a wide-ranging summation of work in all the disciplines involved. It highlights the links in different lines of research, shows what has been achieved to date, and considers the most promising directions for future work.

[Masters Thesis] Compositionality, a unique and fundamental property of human language, emerges from the pressures placed on language as it is learnt and used by consecutive generations – the pressure for learnability, arising from the transmission process, and a pressure for expressivity imposed by the use of language to convey meaning. This study uses human diffusion chains to explore the contribution that learning and communication make to the cultural evolution of linguistic structure. Languages are exposed to either a learning pressure, a communication pressure, or both. The language in the communication chain became expressive and showed varying degrees of structure, in some cases deliberately introduced as an aid to comprehension. This puts the focus back on the cognitive processes of language users, and emphasises the role of recipient design in the emergence of structure in language. The languages in the learning conditions struggled to maintain a significant degree of structure, contrary to expectations. However, the development of the languages provides clues about the way that language adapts in response to the particular communicative and learning environment.

[Masters Thesis] This dissertation presents the results of a series of simulations intended to expand the findings of Burkett and Griffiths (2009, 2010), whose model is shown to make a number of assumptions that may be unrealistic with regard to human language learners. These assumptions are modified to create a number of more realistic scenarios. A series of simulations shows that the concentration parameter if continues to affect the outcome of iterated learning with Bayesian learners in these new scenarios. To overcome the need for the concentration parameter to be specified by the modeller, a model is presented where agents learn a complex hypothesis composed of both a distribution of languages within a population and the appropriate value for. The outcome of the simulations based on this model are inconclusive but do hint at the possibility of _ being affected by iterated learning, potentially enabling learners to acquire a complex hypothesis.

Storytelling, both factual and fictional, is a universal, cross-cultural phenomenon, largely characterised by one or more intentional agents interacting with unexpected events. Frequently, the protagonist achieves his or her goal, resolving the tension created by the unexpected event. The form of the story—both in conversational event reporting and fictional literature—has undergone cultural evolution to attract attention from others, and as such reflects human cognitive biases. It has been hypothesised that language evolved in part to advertise biological relevance through narrative style event reporting. Thus, it is conceivable that human language and intelligence evolved out of a need to advertise and recognise resourceful individuals. Evolutionary theories of Machiavellian intelligence in early humans support this position. The present study partially replicates Mesoudi et al.’s (2006) transmission chain study, which showed that participants more accurately remember stories about social interactions than stories about individual agents. It was concluded that humans have an evolved bias for social information, but not specifically gossip-like information. The present study hypothesised that the individual information did poorly because its protagonist failed to achieve her goal, while she was unexpectedly successful in the social narratives. While there was no significant difference discovered between successful and unsuccessful individual stories, there was also no clear distinction in recall accuracy between social and non-social stories, and gossip was recalled with far greater accuracy than the social story. These results suggest that while humans most likely do have a social bias, other narrative factors such as unexpectedness and high-stakes vs. low stakes scenarios also come into play.