Equality among the sexes leads to more sex, a worldwide study shows.
The study, involving 317,000 international survey respondents, found people who live in countries with higher gender equality have more sex than those living in places with less.
"Women's sexuality has a kind of value that men's sexuality does not," psychologist Roy Baumeister of Florida State University told USA Today. "Men will basically exchange other resources with women to have sex, but the reverse doesn't work."
Using data from 37 countries, residents in areas with higher gender equality tended to have more casual sex, more sex partners per capita, younger ages for first-time sex and a greater tolerance of premarital sex.
"In countries where women are at a big disadvantage, they restrain sex, so the price is high and men make a lifetime commitment to support them to get sex," he said. "Men will do whatever is required for sex."
The research was published this summer in the Journal of Social Psychology.