E-Mail A lot of people think regret must be a good thing because it helps you not repeat a mistake, right? But that turns out not to be the case. Not even when it comes to casual sex, according to new research from the Norwegian University of Science and Technology's (NTNU) Department of Psychology. "For the most part, people continue with the same sexual behaviour and the same level of regret," says Professor Leif Edward Ottesen Kennair. So, we repeat what we thought was a mistake, and we regret it just as much the next time around. Professor Kennair and colleagues professor Mons Bendixen and postdoctoral fellow Trond Viggo Grøntvedt have investigated whether sexual regret is functional, that is, whether it contributes to any change in behaviour.