The Blessing of Sexuality: Evolution of Altruism with Mating Preference

Abstract

Current simulation practices in artificial societies typically ignore the contribution of sexuality as a driving force for the evolution of prosocial behaviours. As recent researches in biology and genetics argued, sexual attractiveness, via the method of sexual selection, can explain many aspects of the second-order so- cial dilemma. The basic hypothesis is that altruism is a sexually attractive virtue. To introduce the hypothesis intotheanalysisofhumanaltruism,weemploytheconceptsofaltruisticpunishmentandthebehaviour-based sexualattractivenesstodevelopagender-basedevolutionarymodelwherematingpreferenceactsasthecom- pensationtothemalepunishersfromfemalesinthegivenpublicgoodsgame. Inthemodel,theforceofsexual selection is expressed as the eect of mating preference on altruism. The computer simulation indicates that social cohesion can be achieved by the existence of sexuality in an artificial society where the co-evolution of mating preference, altruistic punishment and cooperation exist. We then extend the model in two ways: (1) we employthevariablesizepopulationassumptiontotesttheinvasioncapacityofcooperators,and(2)individual variation in altruistic investment is introduced to replace the average population payo function in the base- line model. The variable size population and individual variation in investment are found to have amplifying eects on the evolution of altruism from dierent perspectives. Finally, we discuss the definition of altruism in dynamic evolutionary games, as well as the gender dierences in the formation of altruism in primitive tribes.