Study Says Women Fall Asleep More Often After PIV Sex
A recent study published in Evolutionary Behavioral Sciences found that women fall asleep more often after penis-in-vagina (PIV) sex than men do. According to the researchers, the reason why may have to do with increasing chances of conception as part of human evolution.
The theory goes like this: Because humans are bipedal, getting up and walking around after heterosexual sex may is not always conducive to getting pregnant because of the forces of gravity. The researchers theorized that lying down and falling asleep may increase the odds of conception due to sedative-like properties in seminal fluid. So women adapted to become sleepy after sex to increase their chances of getting pregnant.
To study who falls asleep sooner, researchers recruited 300+ college students to take a survey on their post-sex experiences. They excluded anyone who engaged in non-heterosexual sex and anyone without sexual experience because they wanted to look strictly at sex that leads to conception. They also rejected anyone who had sex in the day time more than in the evening.
Participants completed a survey that asked a series of questions including who falls asleep sooner after sex, them or their partner; how often they fall asleep after PIV sex that results in orgasm; how often they fall asleep after PIV sex with no orgasm; and how often they orgasm, in general. The results showed that people who had an orgasm fell asleep more often than when they didn’t.
The researchers found no gender differences in the “sedative properties of masturbation.” They also found, among the college students surveyed, 50 percent of the men always orgasmed during sex while only four percent of the women did.