Researchers long ago established a link between having sex and feeling pleased with yourself and the world. In a representative recent study of 1,000 women, for example, the participants ranked sex as No.1 among the activities that made them the happiest. Data from 16,000 American adults on incomes, sexual activity and happiness led economists to conclude in a much-discussed 2004 study that increasing the frequency of intercourse from once a month to once a week increased happiness to the same extent as having an additional $50,000 in the bank.
But while these and similar studies, which relied on surveys, revealed an association between sex and happiness, they did not show that more sex actually causes greater happiness. Perhaps happier people just happen to have more sex. To establish causation, scientists needed to get couples to have sex more often and then see if that made them happier.
Turns out it may not, according to a new study in the August issue of The Journal of Economic Behavior & Organization.
For this study, researchers at Carnegie Mellon University and elsewhere recruited 64 adult couples, all married and heterosexual, and asked the volunteers how often they had sex, how enjoyable it was and how happy they were in general, based on standard questionnaires that measure mood and energy. Half the couples, picked randomly, were assigned to go about their lives as usual; the rest were told to double the frequency of sexual relations. If they had sex once a month (the minimum rate for inclusion in the study), make it twice; couples who had sex three times a week (the maximum rate for participants) were to go to six.
The subjects were also tasked with completing a short daily online questionnaire for the experiment’s duration, which was 90 days, about the amount and quality of their sex the previous day and their subsequent moods. Some couples in the experimental group actually did manage to double the rate of intercourse, and on average there was a 40 percent increase.
This did not make them happier. In fact, their well-being declined, especially in measures of energy and enthusiasm, as did the quality of the sex. Both men and women reported that the additional intercourse wasn’t much fun. The results surprised the researchers — but they probably shouldn’t have, according to George Loewenstein, a professor of economics and psychology at Carnegie Mellon, who led the study.
‘‘It seems that if you’re having sex for a reason other than because you like and want sex,’’ he says, you may undermine the quality of that sex and your resulting mood.
The lesson is not simply to avoid participating in academic sex studies. Instead, Dr. Loewenstein says, concentrate on quality rather than quantity if you wish to be happy. Studies associating sexual frequency and happiness may have missed the underlying link between the two, which is the pleasurability of the sex. People who like their couplings probably have more of them, and it is the pleasure of the act, he says, that raises moods, not how often it happens.
This column appeared in The New York Times Magazine on June 28, 2015.
The Joy of (Just the Right Amount of) Sex – The New York Times.