Sperm competition

Over human evolutionary history, men faced the adaptive problem of cuckoldry, or
the unwitting investment in genetically unrelated offspring. As cuckoldry is
potentially so reproductively costly, men may have evolved anti-cuckoldry
psychological adaptations. Sexual coercion has been hypothesized as one class of
anti-cuckoldry behaviors. By sexually coercing an intimate partner, a man may
reduce the risk of cuckoldry by placing his sperm in competition with a rival male's
spenn, should his partner have been sexually unfaithful. I will present three studies
that investigate the role of female infidelity, an assessment of risk of spenn
competition and subsequent cuckoldry, in predicting male sexual coercion in the
context of an intimate relationship.

Guarding oneself from cuckoldry can be a challenging task for males of socially monogamous species. Accordingly, human males may possess evolved psychological mechanisms designed to prevent their partner's infidelity, and to "correct" that infidelity if it occurs. Because preventative tactics are not failsafe, I hypothesized that men's reports of their mate-retention behaviors and copulation frequency would function as complimentary tactics (Study 1). Research has suggested that men's reports of their own anti-cuckoldry behaviors can be flawed, and that women may be more accurate. Therefore, Study 2 analyzed reports made by women of copulation frequency and their partner's mate-retention behaviors. In the two studies, the hypotheses that (1) men's reports of copulation frequency and their own mate-retention behaviors and (2) women's reports of copulation frequency and their partner's mate-retention behaviors would show positive correlations was supported. Discussion focuses on the use of copulation frequency and mate-retention behaviors as complimentary tactics in solving the adaptive problems of sperm competition and cuckoldry.

Sperm competition occurs when the sperm of multiple males concurrently occupy a female's reproductive tract and compete for fertilization. Sperm competition may have been a recurrent adaptive problem over human evolutionary history. Women's orgasm may facilitate retention of a particular man's sperm. I therefore hypothesized that men experiencing greater sperm competition risk will be particularly interested in the occurrence of their partner's copulatory orgasm. Men who are more satisfied with and invested in their relationship may experience greater costs in the event of sperm competition and potential cuckoldry. Therefore, these men may be more interested in ensuring their partner's copulatory orgasm. I hypothesized that men's relationship satisfaction and investment would predict interest in their partner's copulatory orgasm and moderate the link between sperm competition risk and interest in partner's copulatory orgasm. Using data secured from 229 men in a committed relationship, I tested and found support for these hypotheses.