HuffPo Primate Psychology

Gonadal hormones regulate the ability to copulate in most mammalian species, but not in primates because copulatory ability has been emancipated from hormonal control. Instead, gonadal hormones primarily influence sexual motivation. This separation of mating ability from hormonally modulated mating interest allows social experience and context to powerfully influence the expression of sexual behavior in nonhuman primates, both developmentally and in adulthood. For example, male rhesus monkeys mount males and females equally as juveniles, but mount females almost exclusively as adults. Having ejaculated with a female better predicted this transition to female mounting partners than did increased pubertal testosterone (T). It is proposed that increased pubertal T stimulates male sexual motivation, increasing the male's probability of sexual experience with females, ultimately producing a sexual preference for females. Eliminating T in adulthood reduces male sexual motivation in both humans and rhesus monkeys, but does not eliminate the capacity to engage in sex. In male rhesus monkeys the effects of reduced androgens on sexual behavior vary with social status and sexual experience. Human sexual behavior also varies with hormonal state, social context, and cultural conventions. Ovarian hormones influence female sexual desire, but the specific sexual behaviors engaged in are affected by perceived pregnancy risk, suggesting that cognition plays an important role in human sexual behavior. How the physical capacity to mate became emancipated from hormonal regulation in primates is not understood. This emancipation, however, increases the importance of motivational systems and results in primate sexual behavior being strongly influenced by social context.
It is suggested that sex differentials in the probable nature of hostile threats from conspecifics in the human ancestral environment may be reflected in the content of persecutory delusions, especially the identity of persecutors and the nature of threats. If the necessary assumptions hold, men would tend to identify physically violent gangs of strangers as their persecutors, while women would tend to identify their persecutors as being familiar females whose persecution took the form of social exclusion and verbal aggression. Predictions concerning identity were confirmed in a sample of 11 female and 13 male cases identified by retrospective analysis of several hundred case note summaries: 73% of women identified familiar people as their persecutors while 85% of men identified strangers. Information was inadequate to evaluate the nature of persecutory threats.

These preliminary findings invite replication and further exploration in larger, prospective, more extensive and more rigorously-controlled studies.

Sex and Context: Hormones and Primate Sexual Motivation by Kim Wallen

Sex Differences in the Content of Persecutory Delusions: A Reflection of Hostile Threats in the Ancestral Environment?  by Florence Walstona, Anthony S. Davidb, Bruce G. Charlton

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