(CNN) — What makes a woman want to have sex? Is it physical attraction? Love? Loneliness? Jealousy? Boredom? Painful menstrual cramps?

Many women interviewed were having sex purely because they wanted the experience.

It turns out that woman have sex for all of these reasons and more, and that their choices are not arbitrary; there may be evolutionary . . . → Read More: Love, pleasure, duty: Why women have sex