Have you always wondered why your guy "conks out" after sex? Well, The Cosmopolitan School of Paranoid and Heteronormative Science is prepared to legitimize all your endless ruminations and fears. According to a paper published in the Journal of Social, Evolutionary, and Cultural Psychology, partners who go to sleep directly after intercourse are just not that into you or they don't want to commit or they are actually really in love with you and are just scared of losing you. So, basically, his rolling over and promptly hitting the hay post-coitus can mean anything you want: all those Carrie Bradshaw GIFs you post on your tumblr about "living" and "loving" and "finding your Big" are exactly right.
The newest study, published by researchers Daniel Kruger of the University of Michigan and Susan Hughes of Albright College, explores a phenomenon the co-authors call the Post-Coital Time Interval, or PCTI. Kruger and Hughes asked 456 undergraduate participants to complete anonymous online surveys which contained questions assessing their sexual experiences with their partners. The study found that regardless of stereotypes, there was no difference as to which gender fell asleep faster, but that men would stay awake longer if sex didn't take place.
Things get wacky when the researchers start making guesses as to why these behaviors appear: the paper also tries to argue that falling asleep "may be a non-conscious mechanism that forecloses on any commitment conversation occurring after sexual intercourse," before continuing the rampant speculation:
Perhaps men may stay awake longer as an artifact of mate guarding, ensuring that their partner does not secretly leave them for another man. Men may also remain awake longer in attempts to entice their partners to engage in sex. As the costs and benefits of sexual acts are different for men and women, women may have an incentive to fall asleep earlier to decrease the likelihood of sexual acts in most circumstances.
Somehow, a lack of post-coital cuddling also becomes about the man's deep-rooted fears of losing his partner:
If men actively avoid commitment promises in post-coital conversation, this could increase the likelihood of women ending the relationship due to perceptions of undesirable partner characteristics and/or uncertainty about the future of the relationship. Hastening sleep onset may evade this adverse effect.
But as io9 explains, the study contains some serious flaws. While the study initially had 465 participants, 181 of them were eliminated for "not yet having full sexual intercourse" or for expressing same-gender desires. Thus, the study can only be applied to heterosexual couples. Furthermore, the researchers' conclusions are based upon theories of evolutionary psychology, a science that argues that modern behaviors are shaped by evolved reproductive strategies. (Essentially, all women are searching for a provider/protector and all men feel the need to sow their seed.)
While Kruger and Hughes' paper is interesting, it does make some pretty liberal assumptions that I'm just not willing to get behind. Besides, I don't need any more anxiety and self-consciousness between the sheets — I just started letting him leave the light on. Baby steps.