© 1981 by The Society for Integrative and Comparative Biology
Olfaction, Sexual Behavior, and the Pheromone Hypothesis in Rhesus Monkeys: A Critique1
Wisconsin Regional Primate Research Center Madison, Wisconsin 53706
SYNOPSIS. Evidence in support of and contrary to the hypothesis that rhesus monkeys possess a sexual pheromonal system is presented and discussed. New evidence demonstrates that solicitations of females given estradiol are more attractive to males in part because the females allow males to mount much more frequently only when the females have initiated the sexual interaction. In addition, evidence is presented which demonstrates that an odorous control substance stimulates sexual activity just as well as the purported "active component" of vaginal secretions under restricted conditions of evaluation. Finally, preliminary evidence suggests the possibility that odorous products from the vagina, unrelated to short-chain aliphatic acids, present qualitatively distinct cues to the male during the periovulatory phase of the menstrual cycle. However, only sexually experienced males, and not young adult "virginal" males nor adult isosexually-reared males, selectively attended to midcycle vaginal products when these were placed on environmental surfaces. It is concluded that male rhesus monkeys may utilize odorous cues from the female during sexual interactions, but these cues are neither necessary nor sufficient for the coordination of fertile matings. Furthermore, olfactory communication in this species does not fit the accepted definition of pheromone: the odors are not specific for one species; the behavior elicited is not specific to sexual arousal; and volatile materials other than vaginal products can stimulate sexual activity.