On the Theory of Gene-Culture Co-Evolution in a Variable Environment

Abstract

While some social scientists have appreciated the interactions between genetic and cultural evolution, the genetical evolution of behavior and the cultural evolution of human societies have been, for the most part, treated as distinct fields of inquiry. In their recent book Genes, Mind, and Culture , Charles Lumsden and E. O. Wilson argue that genetic and cultural evolution are tightly coupled one to another. The basic premise of Lumsden and Wilson's argument is both simple and compelling. An individual's chances of survival and reproduction depend on his or her behavior, but the decision to adopt one behavior or another is influenced by both the individual's genotype and by his or her social environment. Thus, the social environment influences the relative Darwinian fitness of individuals and, thereby, influences the course of genetic evolution. The Lumsden and Wilson model is analyzed in the chapter by considering three shortcomings of their model of gene-culture co-evolution: (1) the gene-culture co-evolution model is complex, (2) Lumsden and Wilson consider gene-cultural co-evolution only in a constant environment where a particular behavior always has the same fitness consequences, and (3) Lumsden and Wilson consider only the situation where an individual's decision to adopt one behavior or another is influenced by the relative numbers of behavior users in the social environment and not at all by the relative success of individuals that adopt different behaviors.