Evolution is the reason why women regret having one night stands, and men regret not having more

Tinder has made hookups a cake walk--you can match with just anyone with a single swipe. However, women often end up feeling guilty after casual encounters. If you thought it was because of the societal implications of one-night stands , then you are wrong.

According to a recent study, a woman's body is wired to feel guilty after waking up in a stranger's bed. Yes, even evolution is against us having a night of casual fun.

The study conducted by researchers at Norwegian University of Science and Technology's (NTNU) department of psychology has found that women regret agreeing to a one-night stand more often than men. But, men regret passing up the chance more than women do.

"Due to selective pressure from the big difference in parental investment, one would expect men and women to regret different aspects of casual sex decisions," Prof Leif Edward Ottesen Kennair of NTNU said.

In the study, only one-third of women said they were pleased with their casual sex experience, compared to over 50% of men who shared the same sentiment.

According to the researchers, the evolutionary psychology behind one-night stands is due to years and years of gender differences. The scientists also said that the gender difference arises from opposing sexual strategies adopted by the two sexes. As women carry children, our fundamental relationship with sex is much different than that of our male counterparts.

"We're not saying that there aren't men who regret casual sex. But it is far more common for women to regret saying yes. They are also less unequivocally happy about the experience," Kennair added.

The scientists found that eight in 10 women said they were glad that they had said no to a recent opportunity for casual sex, compared to just 43% of men. Men in the study were also found to enjoy the sex more, with more men saying they had orgasmed as compared to women.

The team said that women worry more in general about making spontaneous decisions, and mostly do not engage in actions which put them in danger. Women also worry about becoming pregnant, STIs, and getting a bad reputation--all of which leads to more regrets as compared to men.

So girls, the next time you are making that dreaded walk of shame the morning after, don't be too hard on yourself. Just blame it on evolution!