CULTURE AND THE EVOLUTION OF SOCIAL-LEARNING

Applications of modern evolutionary theory to human culture have gener ated several different theoretical approaches that challenge tradition al anthropological perspectives. ''Cultural selection'' and ''mind par asite'' theories model culture as an independent evolutionary system b ecause transmission of cultural traits via social learning is distinct from transmission of genes via DNA replication, ''Dual-inheritance'' and ''co-evolution'' theories model culture as an intermediary evoluti onary process that involves information from two inheritance systems: genetics and social learning, ''Evolutionary psychology'' theories emp hasize that the evolutionary history of natural selection on mental pr ocesses links culture and biological adaptation; hence, cultural infor mation is viewed as part of the organic phenotype and not an independe nt evolutionary system, Cross-cultural universals and scenarios of the ''environment of evolutionary adaptedness'' are used to identify char acteristics of the ''evolved mind'' (human nature). ''Behavioral ecolo gy'' theories examine relations between behavior and environmental con text, Behavioral/cultural variations are viewed as products of flexibl e decision-making processes (evolved mind) that may respond adaptively to micro-environmental differences, It is difficult to devise empiric al tests that distinguish among these theories, because they share man y basic premises and make similar predictions about human behavior. In deed, some of the apparent differences may be more semantic than subst antive. Social learning is the key process underlying these evolutiona ry paradigms, Here I argue that human learning mechanisms are products of natural selection, and hence process information in ways that refl ect evolutionary design, I review common objections to this hypothesis , including (1) learning processes are uncoupled from genetics and bio logical adaptation; (2) culture (or its effects) is partly extrasomati c; (3) culture, by most definitions, involves mental phenomena, includ ing conscious thought; (4) culture involves the use of arbitrary symbo ls to communicate information; (5) culture appears to have emergent pr operties at the group level, such as shared values and beliefs resulti ng in political and religious institutions; (6) culture involves histo rical processes; and (7) complex culture is uniquely human-we need an explanation for why the human species alone evolved such extensive soc ial learning aptitudes. I suggest that these controversies can be reso lved, although empirical tests are difficult. I posit that social comp etition was a primary selective pressure on human mental abilities (Al exander 1989) and that this favored domain-general, constructivist lea rning capabilities (e.g., Quartz and Sejnowski, in press) that can man age context-dependent analysis and integrate information from domain-s pecific mechanisms (Hirschfeld and Gelman 1994; MacDonald 1991; Sperbe r 1996). Humans are unique in the extraordinary levels of novelty that are generated by the processing of socially learned information. Huma n culture is cumulative; human cognition produces new ideas built upon the old. To a degree that far surpasses that of any other species, hu man mental processes must contend with a constantly changing informati on environment of their own creation. Cultural information may be espe cially dynamic because it is a fundamental aspect of human social comp etition. Apparently arbitrary changes in cultural traits, such as clot hing styles, music, art, food, dialects, and so forth, may reflect inf ormation arms races among social competitors. The remarkable developme ntal plasticity and cross domain integration of some cognitive mechani sms may be products of selection for special sensitivity to variable s ocial context. Human ''culture'' is not just a pool or source of infor mation; it is an arena and theater of social manipulation and competit ion. Studies of human behavior-including language, kinship, mating rel ationships, subsistence, economics, and politics-generally are consist ent with an evolutionary basis for social learning, but often they fai l to add specific new knowledge about the mechanisms. Analyses of cogn itive aptitudes underlying language, kinship, and so forth, often are inconclusive because cultural information (and consequent behavior) in volves complex interaction among history, environmental variation, ont ogenetic pathways of mental processes, and specific context. I suggest that empirical tests of evolutionary culture theory must build upon i dentification of apparent universals and examine individual variabilit y by incorporating developmental psychology, environmental conditions, and social and historical context. This synthesis would benefit from enhanced cooperation between cognitive psychologists and cultural anth ropologists. (C) Elsevier Science Inc., 1997.