Orgasm in female primates

Abstract

The major genital responses of arousal in women are vasocongestion, resulting in tumescence of the vaginal walls, and vaginal lubrication, facilitating penile intromission and thrusting. During orgasm, several involuntary muscular reactions occur, the most adaptive being in the outer third of the vagina and the uterus. Uterine suction of the ejaculate seems to occur when the reproductive apparatus is functioning at full efficiency. Coitus may result in reflex ovulation. Indices of female nonhuman primate orgasm thus far proposed include rhythmic vaginal and anal contractions, hyperventilation, involuntary muscle tension, arm and leg spasms, grimacing, and uterine contractions. Orgasm in our species may exist as a result of phylogenetic inertia, not as a novel response selected duringprotohominid or hominid evolution. A theory for the evolutionary nature of orgasm in women states that the orgasmic vaginal contractions stimulate ejaculation. Reasons for the common asynchrony ofthis adaptive pattern are the usually lowered ejaculatory threshold because of non-species-typical orgasmic frequency in the male, and the frequently delayed female orgasm because of psychological inhibition and/or inadequate control and development of the pubococcygeus.

Macaque Cardiac Physiology Is Sensitive to the Valence of Passively Viewed Sensory Stimuli

“…These approaches assume that the same affective state underlies behaviors that are physically homologous, or occur in similar contexts, across species. While behaviors such as a “grimace” are typically interpreted as reflecting negative experience or submission [55] and often discussed as relating to human “fear” [56], grimaces occur in a wide variety of contexts including those which are likely positive or appetitive (e.g., during orgasm, [57]) and when animals signal that they understand social relationships in the absence of any other affective change [58]. Clearly, objective measures of nonhuman primate affect would go some way towards establishing a firm basis for comparison of human and animal affect and the mechanisms that underlie it.…”

Hominid sexual nature

“…Although all mammal females have a clitoris, there was a conviction confirmed by zoologists' research that most animals, with the exception of the bonobos, chimpanzees (Allen and Lemmon 1981;Wrangham 1993) and macaques (Macaca arctoides) (Chevalier-Skolnikoff 1974) do not feel an orgasm. However, Troisi and Carosi (1998) note that it is possible to cause the orgasm in every primate female through artificial stimulation.…”

Female orgasm and the emergence of prosocial empathy: An evo‐devo perspective

“…Symons () has argued that female orgasm is a potential in all female mammals. An orgasm‐like response has been elicited in other primates experimentally but because of the inability to communicate it is not known if other species experience orgasm as humans do (Allen & Lemmon, ).…”