The Big O: New Scientific Findings on Orgasm

The erotic picture shown above is from the medieval tantric hindu temple in the village of Khajuraho, in the Indian state of Madhya Pradesh 

The male orgasm has an obvious evolutionary adaptation in that an orgasm is necessary for conception and reproduction. Any physical or psychological traits that increase a mans probability for intercourse could be passed to future generations and proliferate throughout the population over time. The female orgasm however has no such obvious evolutionary adoption in that it is not necessary for conception, and the probability of orgasm in woman varies with circumstances.

Sexual practices and occurrence of orgasm. In a national survey of over 19,000 Australians, it was discovered that men had an orgasm in 95% of sexual encounters and women in 69%. Women were more likely to reach orgasm in encounters that included manual stimulation of the genitals and, especially, cunnilingus.[1]

Orgasm and women's relationship quality. The frequency of penile-vaginal intercourse, and corresponding orgasm rates, correlates positively with perceived relationship quality in women. The dimensions of perceived relationship quality included satisfaction, intimacy, trust, passion, love and global relationship quality. Non-coital sexual behaviors with a partner were uncorrelated with perceived relationship quality.[2] 

Emotional satisfaction and physical pleasure. 3,432 heterosexual adults (aged 18-59 yrs) provided information concerning emotional satisfaction, physical pleasure, background characteristics, and sexual behavior, attitudes, and tastes. Results show that married or cohabiting Ss reported significantly more sexual emotional satisfaction and higher levels of physical satisfaction than did single Ss. Emotional satisfaction with sex for both partners was associated with more sex, sexual exclusivity, and female Ss' orgasm frequency. Findings suggest that relationship time horizon and sexual exclusivity are more strongly associated with emotional satisfaction than with physical pleasure, but sexual behavior is similarly associated with both emotional satisfaction and physical pleasure.[3]

Female orgasm and male attractiveness. Women mated to more attractive men reported an orgasm during a greater proportion of copulations than did women mated to less attractive men.[4]

Body concerns and sexual pleasure. Body concerns and body shame negatively affect sexual pleasure and promote sexual problems for both men and women.[5]

Subconscious associations to sex. At the non-conscious level, woman associate sex with submission. These associations, however, reduce subjective arousability and even impair ability to reach orgasm among women.[6]

Genetic and environmental influences. In a study of over 3000 Australian, female twins, it was determined that, overall, genetic influences account for approximately 31% of the variance of frequency of orgasm during sexual intercourse, 37% of the variance of frequency of orgasm during sexual contact other than during intercourse, and 51% of the variance of frequency of orgasm during masturbation.[7]

Sociology of female orgasm. A survey of 202 Western women of reproductive age confirmed the hypothesis that orgasm is a strong motivational force that entices women to engage in sexual interactions. However, it was found that one-night stands are unlikely to result in orgasm and that women believed long-term sexual relationships to be much more likely to result in orgasm. This finding could explain why females are, generally, far less compelled to have one-night stands than males.[8]

Orgasm-induced prolactin secretion. The generation of orgasm by both self-masturbation and coitus produced pronounced increases in plasma prolactin (PRL) concentrations in peripheral circulation, in both males and females. These alterations remained elevated following termination of sexual stimulation. PRL remained significantly elevated 60 min following orgasm. Control Ss experiencing sexual arousal but not orgasm showed no changes of PRL levels, in either males or females. It is concluded that orgasm is followed by a pronounced and long-lasting secretion of PRL, regardless of the method of sexual stimulation.[9]

This is a very clear and important finding. Other hormones are not similarly effected by sexual orgasm. However, the role of plasma prolactin in the circulation is not well-understood.

Brain activation during orgasm. Studies of brain imaging in women indicate increased activation at orgasm, compared to pre-orgasm, in the paraventricular nucleus of the hypothalamus, periaqueductal gray of the midbrain, hippocampus, and the cerebellum.[10]