The evolution of ostensive communication (or: Why chimpanzees tend to fail the object choice task (maybe))
Thom Scott-Phillips (Durham)
Work with Christophe Heintz
Tuesday 31 January 2017, 11:00–12:30
1.17 Dugald Stewart Building
How can an intention to inform another individual be satisfied? One possible answer is to provide directly perceptible evidence of the content. Think, for instance, of a primate display of size and strength: standing on two legs, thumping chest, etc. Another way is to provide not direct evidence for the content itself, but rather evidence for the intention to express the content. If, for instance, Mary eats berries, and suffers no ill-consequences, she provides Peter with directly perceptible evidence that the berries are edible. Alternatively, however, Mary might just mime eating berries. In and of itself, miming provides no directly perceptible evidence for the content – for Mary does not eat the berries. Miming does however provide evidence of Mary’s intention that Peter believe that the berries are edible. This change, from evidence for the content to evidence for the intention, allows for an extremely dynamic form of communication, the existence of which helps to explain why humans are such inveterate communicators, and why the size and complexity of human cultures is different to that of any other species by several orders of magnitude. It was first described by Paul Grice, and receives its most precise and cognitively plausible description in the work of Dan Sperber and Dierdre Wilson.
A key question, particularly from ontogenetic and phylogenetic perspectives, is: In what ecological conditions might communication of this sort emerge? Building on my previous work, I will highlight the important role that cooperative ecologies play in facilitating the emergence of this type of communication. In so doing, I will propose a possible explanation of chimpanzee performance in pointing tasks; and also describe an important but under-discussed feature of ostensive communication that could be profitably used in future experimental studies, particularly those focused on the question of whether any non-human species ever communicates in this way.