Sex will make for a happy couple, according to social psychologists, and you don't even need to do it all that often.

Previous claims, and resulting articles and self-help books, have claimed that more sex equals more happiness but that isn't the case, says the new study hoping to result in articles and self-help books. If you never have sex, you probably hate each other and no one is happy, but forcing yourself to get busy three times a week won't make you three times as happy as doing it once. 

This is psychology, so it is surveys rather than science, but the data was responses of 30,000 Americans collected over four decades and though it can't identify the causal process, nor can it tell is if happy people just have more sex. It was only people in romantic relationships, not singles. And not gay people. Really, it can't tell us anything except that sex is always a popular psychology topic. 

For one part, researchers analyzed survey responses about sexual frequency and general happiness from more than 25,000 Americans (11,285 men, 14,225 women) who took the General Social Survey from 1989 to 2012. The biennial survey, conducted by the University of Chicago, has a nationally representative sample and covers a wide range of sociological issues, including opinions about race relations, religion and sex. For couples, happiness tended to increase with more frequent sex, but this is no longer true after couples report engaging in sex more than once a week. Surveys report that established couples tend to have sex about once a week on average.  

Despite common stereotypes that men want more sex and older people have less sex, there was no difference in the findings based on gender, age or length of relationship.  

Sex may be more strongly associated with happiness than is money. The researchers also conducted an online survey with 335 people (138 men, 197 women) who were in long-term relationships and found similar results as the first study. These participants were also asked about their annual income, and there was a larger difference in happiness between people who had sex less than once a month compared to people who had sex once a week than between people who had an income of $15,000-$25,000 compared to people who had an income of $50,000-$75,000 per year. 

The third part analyzed survey results collected at three time points over 14 years from more than 2,400 married couples in the United States. There wasn't a strong link between sexual frequency and overall life satisfaction, but couples reported more satisfaction with their relationships as sexual frequency increased up to once per week, with no noticeable benefits of engaging in sex more often. 

"Although more frequent sex is associated with greater happiness, this link was no longer significant at a frequency of more than once a week," said lead author Amy Muise, a social psychologist and postdoctoral fellow at the University of Toronto-Mississauga. "Our findings suggest that it's important to maintain an intimate connection with your partner, but you don't need to have sex everyday as long as you're maintaining that connection."

Published in Social Psychological and Personality Science.