title: Sex ratio dynamics and fluctuating selection on personality.
abstract: Fluctuating selection has often been proposed as an explanation for the maintenance of genetic variation in personality. Here I argue that the temporal dynamics of the sex ratio can be a powerful source of fluctuating selection on personality traits, and develop this hypothesis with respect to humans. First, I review evidence that sex ratios modulate a wide range of social processes related to mating and parenting. Since most personality traits affect mating and parenting behavior, changes in the sex ratio can be expected to result in variable selection on personality. I then show that the temporal dynamics of the sex ratio are intrinsically characterized by fluctuations at various timescales. Finally, I address a number of evolutionary genetic challenges to the hypothesis. I conclude that the sex ratio hypothesis is a plausible explanation of genetic variation in human personality, and may be fruitfully applied to other species as well.
authors.affiliation: Biology of Social Behavior Lab-Center for Cognitive Science, Department of Psychology, University of Turin, via Po 14, 10123 Torino, Italy. marco.delgiudice@unito.it
authors.forename: Marco
authors.initials: M
authors.lastname: Del Giudice
mesh_terms: D000367:Age Factors; D005075:Biological Evolution; D005246:Feedback; D005260:Female; D006801:Humans; D008297:Male; D008957:Models, Genetic; D008960:Models, Psychological; D016487:Parenting / Q000523:psychology; D010551:Personality / Q000235:genetics*; D011156:Population Density; D011157:Population Dynamics; D012641:Selection, Genetic; D012744:Sex Ratio; D012725:Sexual Behavior / Q000523:psychology; D013269:Stochastic Processes