Culture and the evolution of social learning

Abstract Applications of modern evolutionary theory to human culture have generated several different theoretical approaches that challenge traditional anthropological perspectives. "Cultural selection" and "mind parasite" theories model culture as an independent evolutionary system because 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 evolutionary process that involves information from two inheritance systems: genetics and social learning. "Evolutionary psychology" theories emphasize that the evolutionary history of natural selection on mental processes links culture and biological adaptation; hence, cultural information is viewed as part of the organic phenotype and not an independent evolutionary system. Cross-cultural universals and scenarios of the "environment of evolutionary adaptedness" are used to identify characteristics of the "evolved mind" (human nature). "Behavioral ecology" theories examine relations between behavior and environmental context. Behavioral/cultural variations are viewed as products of flexible decision-making processes (evolved mind) that may respond adaptively to micro-environmental differences. It is difficult to devise empirical tests that distinguish among these theories, because they share many basic premises and make similar predictions about human behavior. Indeed, some of the apparent differences may be more semantic than substantive. Social learning is the key process underlying these evolutionary paradigms. Here I argue that human learning mechanisms are products of natural selection, and hence process information in ways that reflect evolutionary design. I review common objections to this hypothesis, including (1) learning processes are uncoupled from genetics and biological adaptation ; (2) culture (or its effects) is partly extrasomatic ; (3) culture, by most definitions, involves mental phenomena , including conscious thought; (4) culture involves the use of arbitrary symbols to communicate information; (5) culture appears to have emergent properties at the group level , such as shared values and beliefs resulting in political and religious institutions; (6) culture involves historical processes ; and (7) complex culture is uniquely human —we need an explanation for why the human species alone evolved such extensive social learning aptitudes. I suggest that these controversies can be resolved, although empirical tests are difficult. I posit that social competition was a primary selective pressure on human mental abilities (Alexander 1989) and that this favored domain-general, constructivist learning capabilities (e.g., Quartz and Sejnowski, in press) that can manage context-dependent analysis and integrate information from domain-specific mechanisms (Hirschfeld and Gelman 1994; MacDonald 1991; Sperber 1996). Humans are unique in the extraordinary levels of novelty that are generated by the processing of socially learned information. Human culture is cumulative; human cognition produces new ideas built upon the old. To a degree that far surpasses that of any other species, human mental processes must contend with a constantly changing information environment of their own creation. Cultural information may be especially dynamic because it is a fundamental aspect of human social competition. Apparently arbitrary changes in cultural traits, such as clothing styles, music, art, food, dialects, and so forth, may reflect information arms races among social competitors. The remarkable developmental plasticity and cross-domain integration of some cognitive mechanisms may be products of selection for special sensitivity to variable social context. Human "culture" is not just a pool or source of informational; it is an arena and theater of social manipulation and competition. Studies of human behavior—including language, kinship, mating relationships, subsistence, economics, and politics—generally are consistent with an evolutionary basis for social learning, but often they fail to add specific new knowledge about the mechanisms. Analyses of cognitive aptitudes underlying language, kinship, and so forth, often are inconclusive because cultural information (and consequent behavior) involves complex interaction among history, environmental variation, ontogenetic pathways of mental processes, and specific context. I suggest that empirical tests of evolutionary culture theory must build upon identification of apparent universals and examine individual variability by incorporating developmental psychology, environmental conditions, and social and historical context. This synthesis would benefit from enhanced cooperation between cognitive psychologist and cultural anthropologist.