Women orgasm more readily during sex with a handsome partner, a study of heterosexual couples has found - but what does this mean?, the Conversation asks.
Published in collaboration with The Conversation, a website that features commentary, research and analysis from Australian universities and the CSIRO.
Women orgasm more readily during sex with a handsome partner, a study of heterosexual couples has found, with researchers concluding the female orgasm may be linked to an evolutionary urge to produce 'quality' offspring.
However, other experts in the field say that the jury is still out on the evolutionary function of the female orgasm.
In a joint study by anthropologists and psychologists at Pennsylvania State University, 110 heterosexual couples were asked to report details about their sex lives, who orgasmed and how often.
The male subjects also had details recorded about facial symmetry and masculinity, in an effort to determine their attractiveness.
Women with partners who rated high on the handsome scale reported orgasming more frequently than their less fortunate sisters.
“We found that objective measures of the quality of women's mates — men's attractiveness and masculinity — significantly predicted the women's orgasms,” the researchers wrote in their paper, which was published in the journal Evolution and Human Behavior.
PASSING ON HEALTHY GENES
Assuming that female orgasm aids in conception, the researchers concluded that women may have evolved to orgasm more readily with attractive partners so as to pass on their healthy genes to offspring.
“Thus, possible conception-promoting correlates of female orgasm may be especially effective and/or likely when copulation occurs with masculine males,” the authors wrote.
Brendan Zietsch, a Postdoctoral Research Fellow at University of Queensland who has researched the female orgasm, said the study provided strong evidence that sexy men were more likely to produce orgasms in their female mates – but that this was not necessarily linked to natural selection.
“I do not find it compelling support for this evolutionary function of female orgasm. I would guess that men also orgasm more readily having intercourse with an especially sexy woman, but few would argue that this indicates that the function of male orgasm is to choose the best mate,” he said.
“My point is that arousal being related to both partner sexiness and orgasm frequency is compatible with numerous possible evolutionary explanations of female orgasm.”
He pointed out that the study also found no link between frequency of female orgasm and the man's facial structure in cases of non-reproductive sex – such as orgasm during foreplay – but that this may be because more masculine, dominant men might spend less time on non-coital sex than other men.
“I think we are a long way from understanding the evolutionary function of female orgasm, if indeed it has a function,” he said.
COITAL ORGASM NOT CONSTANT
Dr Maciej Henneberg, Professor of Anthropological and Comparative Anatomy at the University of Adelaide and an expert on evolution, said the study relied too heavily on self-reporting.
“The authors' own findings are that only about half of women (52%) experience coital orgasm. This means it is not a constant feature. Their measures of "genetic quality” of males are purely speculative (appearance, facial asymmetry),“ he said, pointing out that the study may have underestimated other features women may find attractive in men, such as their social or psychological qualities.
One cannot assume that function of female orgasm is to aid conception nor place too much emphasis on the idea that the human libido is driven by the urge to procreate, he said.
“Most of human sexual intercourse is for reasons unrelated to fertility. Moreover, the ability to conceive in humans is low. It takes a persistent copulation every other day for three months to achieve conception, on the average.”
“All this leads to the conclusion that humans use sexual intercourse for bonding and pleasure, rarely for conception,” said Dr Henneberg.
“We are unusual amongst animals in this respect. Only dolphins, pygmy chimpanzees and maybe chimpanzees use sex for social contacts. Other mammals copulate only when a female is fecund (can conceive) and the intercourse takes a short time. We can do it for hours!”