Hierarchical Classification by Rank and Kinship in Baboons

摘要: Humans routinely classify others according to both their individual attributes, such as social status or wealth, and membership in higher order groups, families castes. They also recognize that people's attributes may be influenced regulated by group affiliations. It is not known whether rule-governed, hierarchical classifications are specific humans might occur nonlinguistic species. Here we show baboons a dominance hierarchy can subdivided into family groups. In playback experiments, respond more strongly call sequences mimicking rank reversals between than within families, indicating they simultaneously kinship. The selective pressures imposed complex societies therefore have favored cognitive skills constitute an evolutionary precursor some components of human cognition.