Language Evolution and Computation Bibliography

An important reason to investigate dolphins is that they exhibit striking similarities with humans. Like us, they use tools: dolphins break off sponges and wear them over their rostrum while foraging on the seafloor (Smolker et al 1997). Dolphins are also capable of recognizing their body in front of a mirror (Reiss & Marino 2001). Closely related with their capacity to see through sound is their capacity to form abstract representations that are independent from modality (Herman et al 1998). Dolphins share with us other traits that are appealing from the perspective of language theory. First, they exhibit spontaneous vocal mimicry (Reiss & McCowan 1993) which suggests a predisposition to learn a vocal communication system. Second, they live, in general, in fission‐fusion societies and display complex social behaviours (Lusseau et al 2003, Connor & Krützen 2015) while converging research supports that the complexity of a society and the complexity of communication are correlated (Freeberg et al 2012). Third, they can learn a signal to innovate, namely to show a behavior not seen in the current interaction session (Foer 2015). This tells us something about the limits on memory and creativity in dolphins and is challenging from a theoretical perspective: many researchers believe that a crucial difference between humans and other species is our unbounded capacity to generate sequences, e.g., by embedding sentences into other sentences (e.g., Gregg 2013, Hauser et al 2002), or a capacity for large lexicons (Hurford 2004). In short, bottlenose dolphins share many traits we associate as pre‐requisite for our complex linguistic abilities. Although possessing such an infinite capacity makes a qualitative difference compared to a species with a finite capacity, the fact is that (a) a species being able to generate a huge number of sentences may not be distinguishable from a species that has infinite capacity (supposing that the latter is really true) and (b), humans have problems with parsing sentences with just a few levels of embedding (Christiansen & Chater 2015). The point is that the problem of infinite vs finite capacity does seem to be well poised and that dolphin capacity to innovate is being overlooked. We humans are fascinated by infinity (perhaps for purely aesthetical reasons) and may have rushed to steal the flag of infinity to keep it in some anthropocentric fortress where other species are not allowed to get in. In a recent book, the parallel in cognitive abilities between …

We show that dolphin whistle types tend to be used in specific behavioral contexts, which is consistent with the hypothesis that dolphin whistle have some sort of ameaninga. Besides, in some cases, it can be shown that the behavioral context in which a whistle tends to occur or not occur is shared by different individuals, which is consistent with the hypothesis that dolphins are communicating through whistles. Furthermore, we show that the number of behavioral contexts significantly associated with a certain whistle type tends to grow with the frequency of the whistle type, a pattern that is reminiscent of a law of word meanings stating, as a tendency, that the higher the frequency of a word, the higher its number of meanings. Our findings indicate that the presence of Zipf's law in dolphin whistle types cannot be explained with enough detail by a simplistic die rolling experiment.