Scientists have finally answered the question that has troubled advice columnists for generations: How much sex is the right amount? A paper published in Social Psychological and Personality Science on Nov. 18 found that having sex once a week is linked to happiness, but more than that and there’s no further effect.
A group of researchers led by social psychologist Amy Muise from the University of Toronto conducted three studies on a total of 30,645 participants. The first study, based on 25,510 participants who took part in a nationally representative survey at any point from 1989 to 2012, found that having sex once a week (but no more) was correlated with happiness—though only for those who were in a relationship.
A further two studies were conducted only on participants in relationships, the first with 335 participants recruited from Amazon Turk, and the second based on data from 2,400 couples who took part in a separate survey.
Each study used different scales to measure happiness, and consistently found a significant linear relationship between sexual frequency and happiness for people having sex once a week or less, and no association for those having sex more than once a week.
Terri Fisher, psychology professor emeritus at Ohio State University who was not involved in the study, tells Quartz that though the findings may seem counterintuitive, the conclusion is convincing. Using different measures of happiness in each of the three studies increases its reliability, says Fisher, as does the large sample sizes.
“The study did not examine the relationship between physical pleasure and sexual frequency, however,” she writes in an email to Quartz. Sexual pleasure, rather than frequency, could have a more straightforward relationship to happiness.
Plus, the study shows correlation rather than causation. “It is erroneous to suggest that couples who are having sex more or less often than once a week would suddenly become happier by changing their sexual frequency to one time a week,” adds Fisher.
The findings should come as a relief for those who feel pressure to have a more active sex life. As the authors note in their paper, for couples who juggle work, kids, and other responsibilities “the pressure to engage in sex as frequently as possible may be daunting and even stressful.”
Earlier this year, Rachel Hills published a book, The Sex Myth: The Gap Between Our Fantasies and Reality, arguing that society is gripped by the false belief that everyone is having sex frequently. “We have moved from a culture that told us we were dirty if we did have sex to one that tells us we are defective if we do not do it enough,” she writes.
But as columnists so often advise, there’s no need to fret if you’re not constantly having sex. As the research shows, plenty of couples are perfectly happy with their weekly sex life.