If you've ever been called a slut or a slag, or been scared of being called one, then you know what it feels like to experience the double standards surrounding promiscuity. We've all grown up ...

People often ask what kind of human sexual relationship is most evolutionarily "natural." Is human nature adapted for promiscuity or long-term relationships, for example? And if we're wired for ...

New evidence suggests that Mother Nature has her own means of handling cheating wives. Researchers have found that a gene responsible for semen viscosity has evolved more rapidly in primate species ...

is a popular book about sex and human nature, written by PT blogger Chris Ryan and Cacilda Jethá. Some other PT bloggers seem to be huge fans of the book (for instance, see this recent post by Nadja ...

Females are coy and males are ardent. This was Darwin’s somewhat Victorian portrayal of the sexes in his book The Descent of Man and Selection in Relation to Sex. The myth that males are naturally ...

A little known sexually transmitted infection can boost the survival of patients infected with HIV—a more dangerous virus, researchers say. GB virus C (GBV-C) is the only known case of a potentially ...