Social concepts and communication in nonhuman primates

A major question in science concerns how humans evolved their capacity for language. One approach to answering this question is to take the entire faculty of language as the evolutionarily relevant unit and, by applying natural selection theory, look for evidence of variability, heritability, and adaptive function. Another approach is to conceive of the language faculty as a conglomerate of components with independent evolutionary histories and identify phylogenetic continuities and discontinuities among various components. Here, I follow the second approach, by focusing on comparative research on primate social cognition and communication.Primates have unusually large brains, and the mainstream view is that large brains are an evolved response to prevail in socially complex worlds.Complexity arises from intergroup and intragroup relations governed by reproductive interests, which are mediated by dominance, kinship, and friendship. This chapter reviews field studies that have addressed these topics, focusing on how primates communicate in the wild to ensure their reproductive interests and in relation to evolutionarily important external events, such as food discoveries or predator encounters. The conclusion from this research is that primates can attribute basic mental states to others, such as intentions or perceptions, but the data are less compelling for more complex mental states, such as beliefs or knowledge. I conclude by proposing a research agenda to investigate in more detail the major evolutionary transitions that have paved the way to the emergence of the human language faculty.