Study Offers Evolutionary Perspective on After-Sex Behaviors

There’s evolution at work when she wants to cuddle after sex (and he, well, doesn’t).

That’s the conclusion of a new study, “Sex Differences in Post-Coital Behaviors in Long- and Short-Term Mating: An Evolutionary Perspective,” appearing in an upcoming issue of The Journal of Sex Research.

“The vast majority of the research on the evolutionary psychology of human reproduction focuses on what’s before and leading up to sexual intercourse,” says Susan Hughes, associate professor of psychology at Albright College in Reading, Pa. and author of the study. “But reproductive strategies don’t end with intercourse; they may influence specific behaviors directly following sex.”

There are a number of elements of reproduction happening after the act itself, she points out, including bonding, future relationship intentions (and possible continued sexual activities), sperm retention and competition, mate guarding and the possibility of fertilization.

“We predicted that post-coital considerations are experienced quite differently by men and women due to divergent adaptive reproductive strategies,” she says.

The study, which examined the responses to an online questionnaire given to 170 people, found that women were more likely than men to initiate and place greater importance on behaviors linked to intimacy and bonding with both long and short-term partners. Men were more likely to engage in behaviors that were “extrinsically rewarding” or increased the likelihood of further coital acts.

“Females placed an overall great importance than did males on all five items measured: intimate talking, kissing, cuddling and caressing, professing their love for their partner and talking about the relationship after sex,” says Hughes. “In contrast, men placed more importance on gaining extrinsic rewards after sex (e.g. drinking or smoking, eating, or asking partner for favors). Men also placed more importance on continuing sexual activity than did females.”

Some other highlights of the study:

• Men were more likely to initiate kissing before sex, while women were more likely to initiate kissing after sex. “Kissing is used for both bonding and to increase sexual arousal,” says Hughes. “Men may initiate kissing before intercourse to guarantee sexual access, whereas women may use kissing after sex to help secure the relationship.”

• Sanitary practices after sex (showering, for example) were far more likely to occur with short-term partners than long-term ones. “In terms of evolutionary theory, it’s possible that these are attempts on the part of the female to not retain the sperm for a short-term mate,” she says.

• Females thought intimate talking and discussing the relationship was more important before sex than after. Men’s opinions remained constant for both before and after sex. “This may be a woman’s attempt to assure commitment and investment from her partner before consenting to sex.”

One thing both men and women could agree on? The importance of saying “I love you” to a long-term partner after sex.

“Of all the items measured, it was the only one that didn’t yield any significant sex differences,” says Hughes. “It makes sense that if both a man and a woman want a long-term relationship, they both understand that after sex may be a time of bonding and expressing their love for each other. Men who are in love might realize it’s especially important to their partner that they show their devotion.”

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