Think you should be having more sex? You may want to think again.

A new study published in Journal of Economic Behavior & Organization (leave it to economists to ruin sex) found that when married couples start having 40 percent more sex than usual, their happiness and mood levels actually declined.

How did they do this? Researchers from Carnegie Mellon University recruited 128 men and women to have sex for three months and report back. The couples, married and aged 35 to 65, were split into two groups: a control group, which was given no instructions about having sex, and a second group, which was told to double their weekly sex.

The researchers note that the second group did not fully double their sex but averaged a 40 percent increase over three months. A noble effort, couples.


As part of the process, couples filled out daily questionnaires that aimed to measure their frequency of sex, enjoyment of sex, libido, personality, daily mood, depression, and other items.

At the end of the study, researchers were shocked when they saw that sex enjoyment was correlated with happiness, but sexual frequency was not.

In fact, the couples who increased their sex actually became less happy over the course of three months. These couples also reported having less energy and being more tired.

"The treatment [having more sex] did affect mood, but not in the expected direction," write the researchers in the study. "Those induced by the experimental condition to have more sex displayed a lower mood during the course of the experiment than those in the control group."


The question is: Why? In previous studies, sex and sex frequency has been correlated with happiness (people love sex!)—so what went wrong here?

The researchers hypothesize several reasons for this happiness decline.

First, by forcing couples to double their sex, they created a standard most could not live up to. "Perhaps those in the increased-sex treatment who fail to achieve the sexual frequency target they are given feel inadequate and unhappy," they say in the paper.


Second, the motivation to have sex became less about desire and more about completing a task, which took the fun out of getting between the sheets—and made people want sex less.

"Increased sexual frequency does not enhance (and in fact detracts from) mood because it decreases desire for, and enjoyment of, sex," the researchers suggest in the paper.

Which leads to the most important point. There was a positive correlation between enjoying sex (on a personal level) and happiness, as well as partner closeness as happiness. This suggests that the key to a healthy, joyful sex life is not quantity but quality of the sex.


In other words, mind-blowing sex twice a week is better than mediocre sex five times a week.

The researchers suggest that rather than following the advice of many popular self help books, which urge couples to simply have more sex, couples should instead focus on having better sex.


Their advice: Take more trips, break the usual routine, hire a baby-sitter, or even jet off to a hotel room for the night to spice things up.

Science never sounded so fun.

Taryn Hillin is Fusion's love and sex writer, with a large focus on the science of relationships. She also loves dogs, Bourbon barrel-aged beers and popcorn — not necessarily in that order.