Female sexual arousal: Genital anatomy and orgasm in intercourse

Abstract

In men and women sexual arousal culminates in orgasm, with female orgasm solely from sexual intercourse often regarded as a unique feature of human sexuality. However, orgasm from sexual intercourse occurs more reliably in men than in women likely reflecting the different types of physical stimulation men and women require for orgasm. In men, orgasms are under strong selective pressure as orgasms are coupled with ejaculation and thus contribute to male reproductive success. By contrast, women's orgasms in intercourse are highly variable and are under little selective pressure as they are not a reproductive necessity.. The proximal mechanisms producing variability in women's orgasms are little understood. In 1924 Marie Bonaparte proposed that a shorter distance between a woman's clitoris and her urethral meatus (CUMD) increased her likelihood of experiencing orgasm in intercourse. She based this on her published data which were never statistically analyzed. In 1940 Landis and colleagues published similar data suggesting the same relationship, but these data too were never fully analyzed. We analyzed raw data from these two studies and found that both demonstrate a strong inverse relationship between CUMD and orgasm during intercourse. Unresolved is whether this increased likelihood of orgasm with shorter CUMD reflects increased penile-clitoral contact during sexual intercourse or increased penile stimulation of internal aspects of the clitoris. CUMD likely reflects prenatal androgen exposure, with higher androgen levels producing larger distances. Thus these results suggest that women exposed to lower levels of prenatal androgens are more likely to experience orgasm during sexual intercourse.

Variation in Orgasm Occurrence by Sexual Orientation in a Sample of U.S. Singles

“…Relatedly, sexual roles during sexual activity, which likely vary across sexual orientations and may be particularly gendered in their presentation, may result in differential patterns of individuals reaching, or attempting to reach, orgasm. Yet another possibility could be biological, perhaps related to prenatal androgen and estrogen exposures, which may have varied effects on both sexual orientation [31,32], and separately on vaginal and clitoral anatomy in ways that may also affect orgasm [33]. Only future research can provide further insight into the mechanisms by which sexual orientation influences orgasm.…”

Measuring sperm backflow following female orgasm: a new method

“…However – and contrary to much popular and scholarly opinion – the clitoris is not a Rube Goldberg contraption ill-suited to the production of orgasm through intercourse (Gould, 1987; Hite, 1976; Lloyd, 2005; Symons, 1979; Wallen & Lloyd, 2008; although see Wallen & Lloyd, 2011 for a partial retraction of this position). On the contrary – the clitoris is an exquisitely balanced measuring instrument – with at least 18 separate, but functionally, integrated components (Dickinson, 1949; Kobelt, 1851; O'Connell, Hutson, Anderson & Plenter, 1998; O'Connell, Sanjeevan, & Hutson, 2005).…”

Adaptationism and the Logic of Research Questions: How to Think Clearly About Evolutionary Causes

“…Those women with a longer distance between clitoris and urinary meatus have reliably many fewer orgasms with intercourse than those women with a shorter distance (Wallen and Lloyd 2011). Note again that the occurrence of orgasm is not correlated with fitness measures Santtila 2011, 2013), so these different distances cannot be interpreted functionally, under the present information.…”