Issues in the genetics of social behavior.

The genetics of social behavior presents special difficulties because the phenotype is the product of an interaction between two or more individuals. Social interactions are of two kinds: (1) cooperative, in which the probabilities of transmission of the genes of all participants are similarly affected by the outcome, and (2) agonistic, in which the probabilities for the participants are affected in opposite directions. The latter are of particular interest for evolutionary theory. Three major types of designs for measuring social behavior in genetic experiments are available: (1) homogeneous sets, (2) standard tester, and (3) tester panel representing a reference population. The advantages and limitations of each method are discussed. Important areas for future development include the relationship of genetic and experiential factors in early life to social status as an adult and the extension of the genetic analysis of social behavior to natural populations.