Psychological scientists Saul L. Miller and Jon K. Maner of Florida State University had women wear T-shirts for three nights during various phases of their menstrual cycles. Male volunteers smelled one of the T-shirts that had been worn by a female participant. Some of the male volunteers smelled control T-shirts that had not been worn by anyone.
Saliva samples for testosterone analysis were collected before and after the men smelled the shirts.
The study, published in the Psychological Science, reveals that men who smelled
T-shirts of ovulating women subsequently had higher levels of testosterone than men who smelled the T-shirts worn by non-ovulating women or men who smelled the control shirts.
This biological response may promote mating-related behavior by males, the study said.
In addition, after smelling the shirts, the men rated the odors on pleasantness and rated the shirts worn by ovulating women as the most pleasant smelling.
"The present research is the first to provide direct evidence that olfactory cues to female ovulation influence biological responses in men" the researchers say in a statement.