When it comes to one-night stands, men and women are poles apart. Guys just want, well, you know, while gals go to bed with the false impression of flattery and a craving for feeling desirable.
The upshot, according to new research, is great for most men and the pits for most women. The study goes further under the covers, delving into the nuances of casual sex and its potential as a Venus-and-Mars minefield.
Among the findings: Women were not hooking up in an effort to secure a long-term beau, but because they felt flattered by the overnight proposition.
They were mistaken.
As the researcher points out, men lower their standards when it comes to one-night stands, so the presumed flattery is a fantasy or close to it.
"Often [women] said things like, 'I felt so flattered, so happy that he found me attractive. It was so nice to be wanted,'" said researcher Anne Campbell, a psychologist at Durham University in England. "What women don't seem to see is that men drop their standards massively for a one-night stand."
She added, "No woman should be flattered because a man wants to have sex with her once."
Real feelings, real data
While most research on the topic of casual sex has relied on fictitious vignettes or just having participants imagine they had a one-night stand, the new findings are based on self-reports of feelings following an actual hook-up.
Campbell says in the June issue of the journal Human Nature that the findings suggest women are not well adapted to promiscuity.
Women have much more to lose, while men are in a win-win situation. For the ladies, a baby on the way is a huge responsibility, but a guy can just bail.
"The bottom line is the risks are potentially greater for women," said Todd Shackelford, an evolutionary psychologist at Florida Atlantic University who was not involved in the current study. "It's not surprising they indicate the experience is somewhat less positive, but importantly somewhat more negative."
However, promiscuity does offer natural advantages for women from an evolutionary perspective, Shackelford said. These advantages could explain why women participate in one-night stands even though they feel so lousy afterward.
Flings provide women with the potential to snag the best genes for offspring or they could be spurred by a chemical nudge at the peak of the menstrual cycle.
The morning after
Campbell surveyed more than 3,300 individuals, most of whom were between the ages of 17 and 40. Of the heterosexual respondents, more than half reported a one-night stand, about evenly split between men and women.
Overall women's morning-after feelings were more negative than men's. While 80 percent of men had overall positive feelings, just 54 percent of women had positive feelings.
Women predominantly reported "regret at being used," with additional comments including: "I felt cheap," "horrified afterward," and "I felt degraded. Made myself look cheap and easy. Total regret."
Contrary to popular belief, women said they didn't view casual sex as a prelude to a long-term relationship.
"It's not that they wanted the man to whisk them off and marry them," Campbell told LiveScience. "It's that they wanted the man to understand that they weren't like this normally. That they were doing this for him on this night as a particular event."
Men reported feelings of success since the partner was desirable to others and found the experiences much more sexually satisfying than women did.
Typical positive comments from men included: "euphoric," "excitement and lust," "I believe that one-night stands are a good way of blowing off steam."
For men who reported negative feelings, the prevailing tone was one of emptiness and loneliness.
Why women do it
Why then, if women feel so crappy after a casual roll in the hay, do they hop in again?
They could be collecting healthy genes for their offspring. So even if a woman can't score a lengthy relationship with a guy whose sperm could offer, say, disease-resistant genes or genes for a particular kind of intelligence, her thinking might be, "Why not grab the guy for sex?"
"If you've got a Brad Pitt character - absolutely gorgeous and incredibly loaded with money and so on - the chances of getting him to commit himself to you for the rest of your life are pretty slim," Campbell said. "But the chances of him giving you a half an hour on a Wednesday afternoon in a hotel are probably much better."
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Jeanna served as editor-in-chief of Live Science. Previously, she was an assistant editor at Scholastic's Science World magazine. Jeanna has an English degree from Salisbury University, a master's degree in biogeochemistry and environmental sciences from the University of Maryland, and a graduate science journalism degree from New York University. She has worked as a biologist in Florida, where she monitored wetlands and did field surveys for endangered species. She also received an ocean sciences journalism fellowship from Woods Hole Oceanographic Institution.