Just a whiff of a woman close to ovulation is enough to stimulate another woman's testosterone levels, along with her desire to compete.
Competition among women may be, in large part, nose-driven, as a new study finds that the scent of a woman close to ovulation triggers a testosterone boost in the smelling female.
Testosterone, in turn, can affect behavior.
"It's well known that testosterone is linked to aggression and competitiveness," lead author Jon Maner, a Florida State University psychologist, told Discovery News. "Based on our testosterone findings, one could speculate that women exposed to the scent of ovulation might become more antagonistic or competitive."
For the study, published in the latest issue of the journal Evolution and Human Behavior, Maner and co-author James McNulty measured the testosterone levels of women before and after they smelled t-shirts that were previously worn by other women aged 18-21. The latter group wore the shirts when they were at high fertility -- days 13, 14 and 15 of the menstrual cycle -- and at low fertility- days 20, 21 and 22.