Evolutionary psychologist David Buss of the University of Texas at Austin; study leader Andrew Galperin, a former social psychology doctoral student at the University of California-Los Angeles; and Martie Haselton, a UCLA social psychology professor, said prior researchers focused primarily on the emotion of sexual attraction in sexual decisions.
"These studies point to the importance of a neglected mating emotion -- sexual regret -- which feels experientially negative but in fact can be highly functional in guiding adaptive sexual decisions," Buss said in a statement.
In three studies the researchers asked participants about their sexual regrets. In the first study, 200 respondents evaluated hypothetical scenarios in which someone regretted pursuing or failing to pursue an opportunity to have sex. They were then asked to rate their remorse on a five-point scale.
In the second study, 395 participants were given a list of common sexual regrets and were asked to indicate which ones they have personally experienced.
The last study replicated the second one with a larger sample of 24,230 individuals that included gay, lesbian and bisexual respondents.
The study, published in the Archives of Sexual Behavior, found the most common regrets for women were: losing virginity to the wrong partner (24 percent), cheating on a present or past partner (23 percent) and moving too fast sexually (20 percent).
For men, the top three regrets 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), the study said.
Although rates of engaging in casual sex were similar overall among participants -- 56 percent -- women reported more frequent and more intense regrets.
Comparing gay men and lesbian women, bisexual men and bisexual women, a similar pattern held -- women tended to regret casual sex more than men, the researchers said.