(The following excerpt from Why We have Sex (Beyond The Obvious Reasons) by Elizabeth Bernstein was posted on online.wsj.com on October 21, 2013. To view this post in its entirety click on the link below.)
For many years, scientists believed that humans had sex for a few simple reasons: to reproduce, experience physical pleasure or relieve sexual tension. Then a 2007 study from the University of Texas identified 237 expressed motives for sex. The reasons ranged from the mundane (stress reduction) to the spiritual (to get closer to God) and from the altruistic (to make the other person feel good) to the spiteful (to retaliate against a partner who cheated by cheating).
Now, two studies by University of Toronto researchers published this month in the journal Personality and Social Psychology Bulletin, have divided the most common reasons why people have sex—and the ones most relevant to long-term relationships—into two broad categories of motivation: approach and avoidance. Approach motives pursue a positive outcome. (“I want to increase intimacy with my spouse” or “I want to feel closer to my partner.”) Avoidance motives aim to evade a negative outcome. (“I want to avoid conflict” or “I don’t want to feel guilty.”)
The researchers paid particular attention to partner-focused goals. “They have the greatest impact on the outcomes of a relationship,” says Amy Muise, a postdoctoral fellow at the University of Toronto and lead researcher on the study.
Each category is also divided into subcategories: self-focused or partner-focused.
The results: On days when a person’s motivation to have sex is more positively oriented, he or she felt more satisfied—both in the relationship and sexually—and had a higher level of desire. Conversely, on days when someone was motivated to have sex by more negative goals, he or she felt less satisfied and less desire.
Even more interesting, the researchers say: A person’s sexual motivation affected his or her partner’s gratification. When someone had sex for positive reasons, the partner felt more desire and relationship satisfaction. When someone had sex for negative reasons, the partner felt less satisfied in the relationship and less sexually satisfied.
The researchers found no difference when it came to gender. “Men do have higher desire in general, but the motives for sex and the way they make people feel aren’t different for men and women,” says Dr. Muise.
Also, regardless of how often a couple had sex, the results of the research were the same.