GENETIC SIMILARITY THEORY - BEYOND KIN SELECTION

Genetic similarity theory (GST) is presented, which incorporates the kin-selection theory of altruism under a more general principle. GST states that a gene ensures its own survival by acting so as to bring about the reproduction of any organism in which copies of itself are to be found. Rather than behaving altruistically only toward kin, organisms are able to detect other genetically similar organisms and to exhibit favoritism and protective behavior toward these strangers, as well as toward their own relatives. In order to pursue this general strategy, an organism must, in effect, be able to detect copies of its genes in other organisms. Several data sets are ordered with this theory including kin recognition studies in animals raised apart, assortative mating, intrafamilial relations, human friendship and altruism and ethnic nepotism. A strong and a weak version of GST are discussed and some predictions for future research are offered.