When fruit flies are infected with the Wolbachia bacteria, their sex lives—and ability to reproduce—change dramatically. Arizona State University scientist Timothy Karr decided to find out why. What ...

A pair of brain-imaging studies suggest researchers may be able to predict how likely young adults are to develop problem drinking or engage in risky sexual behavior in response to stress. The new ...

CHICAGO (AP) — Shots that protect against cervical cancer do not make girls promiscuous, according to the first study to compare medical records for vaccinated and unvaccinated girls. The researchers ...

Many believe that most people dislike individuals who have sex with a lot of partners—although one's definition of “a lot” is highly subjective. In study after study, promiscuous people are seen as ...