Altruistic Tendencies are Sensitive to Sex-specific Mate Selection Criteria

Natural selection and sexual selection are usually seen as either two different and separate processes or with sexual selection being a subset of natural selection but distinct from other processes such as kin selection. In this paper, we investigate the possibility of a connection between discriminatory altruistic behaviors consistent with kin selection and the sex-specific criteria that men and women are evaluated on by potential partners in the process of mate selection. Many studies document discriminatory altruistic behaviors consistent with kin selection, including tendencies to favor closely related family members for costly assistance. Considerable research also demonstrates the existence of sex-specific mate selection criteria. When selecting a suitable mate, men show a preference for fecundity cues in women, such as the waist-to-hip ratio, which indicates a woman’s ability to conceive and bear children. Women show a preference for high resource potential and high social status in men, indicating a man’s ability to provide resources for the woman and offspring. We tested whether sex-specific mate selection criteria influences patterns of assistance and whether nepotistic tendencies are stronger for each sex within the domains in which women and men are differentially valued. Undergraduate students reported altruistic behaviors that benefited another individual’s social status, resource potential, or physical attractiveness, as well as the relationship between the participant and whom he or she helped. We did not find evidence for nepotistic tendencies indicative of kin selection. Results did provide moderate support for the hypothesis that sex specific mate selection criteria influences the type of altruistic behavior, although both male and female participants were more likely to provide assistance to those of the same sex overall.