For some people, happiness is curling up for a post-sex snuggle. For others, it's conking out immediately.

Scientists at the University of Michigan and Albright College recruited 456 heterosexual undergraduates to fill out anonymous online surveys about their behavior and their partners' behavior after intercourse. They also were asked to indicate their own feelings about whether there was adequate affection, communication, and bonding in the relationship.

The scientists found that students who wished their partners were more responsive and communicative with them tended to have partners who fell asleep before they did following intercourse.

Why does this matter? The researchers claim that the Post-Coital Time Interval (PCTI) is a crucial and telling factor in sexual relationships, as bonding and commitment are solidified in the time period after intercourse. In fact, the study's authors cite previous research claiming that satisfaction with the PCTI is the single most important aspect of a sexual relationship. Their own research confirmed the importance of the PCTI, with respondents indicating higher satisfaction in this area when their partners showed them more love and evidence of commitment.

Does dropping off to sleep actually cause one's partner to crave some cuddling and conversation? It might. However, the researchers also claim that men in particular may fall asleep in order to avoid the very conversations their mates crave—the ones about love and commitment.

As the popular notion that men fall asleep quickly after sex—and in general avoid commitment—persists, the researchers decided to see if there were gender differences in the students' post-coital desires. Perhaps surprisingly, women were just as likely as men to fall asleep first. One thing was clear, though-women value sleeping with their partner after sex more than men do.

If your relationship is suffering because one of you feels shortchanged emotionally after intercourse, talk to your partner about it. Perhaps a little soft music can keep him or her awake for a while. If despite his or her best efforts your partner just can't stay conscious, focus on increasing your connectedness at other times—during the day, perhaps, or before sex occurs.




Kruger D J and Hughes S M (2011). Tendencies to Fall Asleep First After Sex Are Associated With Greater Partner Desires For Bonding and Affection. Journal of Social, Evolutionary, and Cultural Psychology, 5(4), 239-247.