“For men throughout evolutionary history, every missed opportunity to have sex with a new partner is potentially a missed reproduce opportunity — a costly loss from an evolutionary perspective,” said Martie Haselton, a UCLA social psychology professor who worked on the study.

The three main regrets for men: being too timid to approach a possible partner, not being more sexually adventurous when young and not being more sexually adventurous in their single days.

The main regrets for women include losing their virginity to the wrong partner, cheating on a present or past partner and moving too fast sexually.