If you're the type of person who believes in true love, fate, monogamy, or free will, this post will piss you off. Salon.com recently interviewed the psychology professor Peter K. Jonason on his latest publication, "Positioning the Booty-Call Relationship on the Spectrum of Relationships," in which be breaks sex down to basic economics. Below are his main points from the interview.

-Because females are more biologically invested in offspring, they are choosier regarding sex partners. As a result, men and women have opposing biological impulses when it comes to sex. In one-night stands, men win. In committed relationships, women win. A booty-call is a compromise. It gives women a type of long term relationship while the male receives sex for a relatively low investment. Sex is a negotiation. Neither sex gets exactly what they want.

-Booty-calls are more sexual and include a wider range of sexual acts than one-night-stands, but they involve fewer emotions than one-night-stands. Booty-call partners engage in less