Why do human beings have sex? Surprisingly few scientists have bothered to study this question, likely because it’s one that seems to have an obvious answer: humans have sex for pleasure and for reproduction. But are humans really that simple? Not exactly. In fact, research has found that people report hundreds of distinct reasons for “getting it on!” In this article, I’d like to take a look at some of the most and least common reasons reported for having sex and consider the ways in which they’re similar and different across men and women.

Specifically, let’s consider the results from a recent series of studies conducted by Cindy Meston and David Buss. In their first study, they recruited a sample of 444 men and women aged 17-52 from college classes and the local community in Austin, Texas. Participants were presented with the following open-ended response question: “Please list all the reasons you can think of why you, or someone you have known, has engaged in sexual intercourse in the past.”

Afterward, the researchers put together one large list of reasons in which those that were identical or very similar were combined. The end result was a list of 237 different reasons for sex! Clearly, people aren’t just having sex because it feels good or because they want to make babies.

In a second study, a sample of 1,549 college students were provided with the list of all 237 reasons and, for each one, they were asked to indicate how many of their previous sexual experiences could be attributed to that reason on a scale ranging from 1 (none of my sexual experiences) to 5 (all of my sexual experiences). Below are the 10 most common reasons for sex reported by women and men.