Sexual Conflict and the Operational Sex Ratio

The degree and form of sexual conflict is strongly influenced by the relative proportions of potentially reproductive males and females in a population. Patterns following from the operational sex ratio of groups in other species are reflected in human populations. Because the reproductive strategies of men and women are somewhat divergent, market influences on the intensity of mating competition and selectivity for partners produce different outcomes in female-biased and male-biased populations. Male mating opportunities are enhanced by scarcity, and incentives for long-term commitment are diminished, encouraging serial and simultaneous polygyny. Scarce females may be able to more effectively secure commitment from partners as well as demand higher levels of resource investment. However, male social power often constrains women's ability to leverage their market scarcity for serial or simultaneous polyandry. Imbalanced sex ratios are associated with largely consistent social and cultural trends in specific historical periods and populations.