UCLA researchers found out what most of you probably already know:

Women regret one-night stands, while men regret situations where they might have had a one-nighter, if only they were more aggressive or persistent.

This mind-blowing conclusion is the result of …

… three — count 'em — three studies conducted jointly by UCLA and the University of Texas at Austin researchers.

The academics surveyed 24,000 participants about their sexual regrets. The combined results were published in the latest Archives of Sexual Behavior.

Martie Haselton, a UCLA professor of psychology whose lab was used for the work, says our separate evolutionary aims are to blame:

Women need to be more selective about their lovers because of the heavy investment they historically put into offspring — pregnancy, nurturing, juice boxes.

The three most common regrets for women, according to UCLA's summary:

— Losing virginity to “the wrong partner.” (Nearly one in four women, 24 percent, said this).

— Cheating on a man. (Again, this one was nearly one in four, at 23 percent).

— Moving too fast (exactly one in five said this).

Haselton:

… 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.

Men's top three regrets:

— Failing to make a move (27 percent).

— Not making enough moves when they were younger (23 percent).

— And not not making enough moves when they were single (19 percent).

Men were freer to roam in their caveman days and thus needed to take every opportunity to procreate, apparently. Haselton:

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.

And thus, the frat party is finally explained.

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