research: regreats about sex depends on your gender

The researchers say the findings make evolutionary sense.

"For men throughout evolutionary history, every missed opportunity to have sex with a new partner is potentially a missed [reproductive] opportunity -- a costly loss from an evolutionary perspective," study leader Martie Haselton explained in a University of Texas at Austin news release.

"But for women, reproduction required much more investment in each offspring, including nine months of pregnancy and potentially two additional years of breast-feeding," said Haselton, who is a social psychology professor at the University of California, Los Angeles. "The consequences of casual sex were so much higher for women than for men, and this is likely to have shaped emotional reactions to sexual liaisons even today."

In the study, Haselton's team surveyed nearly 25,000 heterosexual, bisexual, gay and lesbian Americans, and found that the top three most common sexual regrets for men were: being too shy to make a move on a prospective sexual partner (27 percent); not being more sexually adventurous when young (23 percent); and not being more sexually adventurous during their single days (19 percent).

For women, the top three regrets were: losing their virginity to the wrong partner (24 percent); cheating on a present or past partner (23 percent); and moving too fast sexually (20 percent).

More women than men (17 percent vs. 10 percent) listed having sex with a "physically unattractive partner" as a top regret, according to the study published in the Archives of Sexual Behavior.

Rates of engaging in casual sex were similar overall among participants (56 percent), but women in all groups (heterosexual, bisexual and lesbian) had more frequent and intense regrets about it.

Haselton said that differences in men's and women's reaction to sex seem to endure over millennia, even though the context in which people have sex may have changed.

"For example, we have reliable methods of contraception," she said. "But that doesn't seem to have erased the sex differences in women's and men's responses, which might have a deep evolutionary history."