A new study found men and women's attitudes towards intimacy drastically differ when it comes to casual sex.

According to a news release, men are more likely to regret not having sex with a woman they desired that night while women will feel remorse for having relations with a man they barely know.

The research was led by psychologists at UCLA and the University of Texas at Austin, and published in the current issue of the journal Archives of Sexual Behavior.

"For men, throughout evolutionary history, every missed opportunity to have sex with a new partner was potentially a missed reproductive opportunity - a costly loss from an evolutionary perspective," said Martie Haselton in a statement, a UCLA professor of psychology and communication studies in whose lab the research was conducted. "But for women, reproduction required much more investment in each offspring, including nine months of pregnancy and potentially two additional years of breastfeeding. The consequences of casual sex were so much higher for ancestral women than for ancestral men, and this is likely to have shaped emotional reactions to sexual liaisons even today."

The data collected came from three studies where researchers analyzed more than 24,000 participant's feelings about "sexual regrets."  The findings below show the most common regrets among men and women:

The three most common regrets for women, in descending order, 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).

For men, the top three regrets were, in descending order: 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). (Click here to view more study results)

In the first study, researchers gave participants hypothetical situations where casual sex did not happen, but the person either felt remorseful they didn't sleep with the person or they regretted "taking advantage" of someone.  Participants were asked to rate the reactions on a five-point scale.

Researchers used the next study to see which sexual regrets of heterosexual participants had experienced themselves.  The volunteers were given a list of "common sexual regrets" and asked which ones they could relate to, according to a news release.  The final study was exactly like the second, except the responses were taken from people with different sexual backgrounds, i.e. those who were heterosexual, gay, lesbian and bisexual.

"We do not doubt that social norms, such as a sexual 'double standard,' play a major role in sexual regret," said lead author Andrew Galperin in a statement, who worked on the project before completing his Ph.D. in psychology at UCLA in 2012. "But these norms themselves might have roots in the ancient selection pressures shaping women's and men's minds."