MARITAL ASSORTMENT FOR GENETIC SIMILARITY

The present study involved analyses of a Caucasian American sample (n=949) and a Japanese American sample (n=400) for factors supporting Genetic Similarity Theory (GST). The analyses found no evidence for the presence of genetic similarity between spouses in either sample for the blood group analyses of nine loci. All results indicated random mating for blood group genes. The results did not provide consistent substantial support to show that spousal similarity is correlated with the degree of genetic component of a trait for a set of seventeen individual differences variables, with only the Caucasian sample yielding significant correlations for this analysis. A third analysis examining the correlation between presence of spousal genetic similarity and spousal similarity on observable traits was not performed because spousal genetic similarity was not observed in either sample. The overall implication of the study is that GST is not supported as an explanation for spousal similarity in humans.

An Integrative Evolutionary Perspective on Ethnicity

This paper integrates several different but mutually consistent evolutionary approaches to ethnicity: genetic similarity theory, social identity theory, individualism/collectivism, an evolved racial/ethnic human kinds module, and rational choice mechanisms relying on domain general cognitive mechanisms. These theories are consistent with each other, and together they illustrate the interplay of evolved cognitive and motivational systems with mechanisms of rational choice that are able to choose adaptive strategies in uncertain, novel environments.

Strategies of Co-operation: A Commentary

The papers in this special section illustrate the subtle interweaving of co-operation and competition as individual strategies, in primates and humans. These strategies can be strongly influenced by cultural context, and by individual/relational characteristics. The Charlesworth/LaFreniere paradigm provides opportunities for examining these, and could be analysed further in games theory terms; as can alternative paradigms. Friendship is one important relational characteristic, and its causal links to reciprocity might be examined further in terms of attachment theory and genetic similarity theory. An attachment theory approach may give insight into cultural differences in the co-operation/competition balance.