In What Kinds of Social Groups can “Altruistic” Behaviors Evolve?

Altruistic behavior represents a puzzle from an evolutionary point of view. Kin selection and reciprocal altruism can explain altruism only in restricted contexts. We present simulations showing that altruistic behaviors can emerge in social groups of individuals that behave similarly because they are genetically related but not in random social groups. We suggest that if homogeneity of behavior within group can be guaranteed by some cultural mechanism, altruistic behaviors can emerge and be maintained in the population.