PRIMATE COGNITION - COMPARING PROBLEMS AND SKILLS

Primate cognition is believed to have adapted during evolution in resp onse to complexity, stemming from either social or environmental chall enges. Arguments favoring one or another domain as the predominant spu r to increased intelligence have been proposed on the basis of the inh erent complexity of problems facing primates and the sophistication of their observed behavioral response. A review of recent findings shows that cognitive differences between primates are well revealed by natu rally posed problems. Current evidence shows a sensitivity to fine soc ial distinctions in haplorhine primates, associated with complex socia l manipulations and neocortical enlargement, compared to strepsirhines . Several aspects of foraging behavior also suggests cognitive sophist ication in various primates. Depth of understanding, however, is great er in great apes than in monkeys; this applies to both spheres, social (e.g., comprehending mental states) and nonsocial (e.g., comprehendin g physical mechanism and hierarchical organization of behavior). The i ncreased representational understanding in great apes is not associate d either with more manipulative social actions or with neocortical enl argement, compared to monkeys. This evidence supports theories of a so cial origin of cognition for those aspects shared by monkeys and apes but not for the unique qualitative differences of great apes. Task com plexity is difficult, perhaps impossible, to measure or compare across domains; any such comparison would certainly be premature at present for primates. Behavioral skill, though in principle simpler to compare , is at present difficult to assess when there is no common currency o f theory-building. With the aim of encouraging comparisons of data fro m laboratory and field and from social and technical problems, a preli minary exploration is made with a notation derived from artificial int elligence; this is shown to be capable of representing theories of com plex behavior in both social and technical domains. (C) 1995 Wiley-Lis s, Inc.