According to scientists, the emergence of AIDS and the boom led to the divorce of their parents that they are less prone to "free love" and more valued loyalty.
Those that were born before the 1960s, the invention of the pill has awakened a sense of sexual adventure. But this led to a large number of failed relationships - and convinced the "Generation X" beware of adultery.
However, teenagers and those who are now a little over 20, have not received such a lesson: for them, sex is often a means of entertainment thanks to the internet, says Edward Lohman, a sociology professor at the University of Chicago, who led the study.
"It is clear that the" Generation X "has sexual intercourse, but it is clear that this does not happen often, and not in a way as their parents or current teenagers and students," - he said.