14 January 2010

Male testosterone levels surge with ovulation

by Kate Melville

Instead of using perfume to attract a mate, women may be better off going au naturel, say researchers from Florida State University who observed surges in testosterone when men were exposed to ovulatory odors.

Scientists have known for some time that testosterone levels in male animals are influenced by the odor signals emitted by females. Researchers Saul L. Miller and Jon K. Maner wanted to see if a similar response occurs in humans. In two studies, women wore tee shirts for 3 nights during various phases of their menstrual cycles. Male volunteers smelled one of the tee shirts that had been worn by a female participant. In addition, some of the male volunteers smelled control tee shirts that had not been worn by anyone. Saliva samples for testosterone analysis were collected before and after the men smelled the shirts.

The results, published in Psychological Science, revealed that the men who smelled the tee shirts of ovulating women subsequently had higher levels of testosterone than men who smelled tee shirts worn by non-ovulating women or the men who smelled the control shirts. Additionally, after smelling the shirts, the men graded the odors on pleasantness and rated the shirts worn by ovulating women as the most pleasant smelling.

The study suggests that testosterone levels appear to be responsive to odors indicating when a woman is fertile. "[This] research is the first to provide direct evidence that olfactory cues to female ovulation influence biological responses in men," note the researchers.

Related:
Ovulation triggers female risk-taking behavior
Unnatural selection: Courtesy of The Pill
Red makes men behave "like animals"

Source: Psychological Science