A woman's tears can be a total turnoff for a guy if he smells them, according… (Associated Press / Science )
A woman's tears can be a total turnoff for a guy — if he smells them, that is.
Men who sniffed the tears of weeping women produced less testosterone and found female faces less arousing, according to new research that suggests a novel evolutionary explanation for why humans cry.
Communication isn't limited to language, said neuroscientist Noam Sobel of the Weizmann Institute of Science in Rehovot, Israel, whose study was published online Thursday by the journal Science. "And here, we've uncovered the chemical word for 'no,' or 'not now.' "
Emotional tears previously had been shown to be chemically distinct from reflexive, eye-protecting tears. And in animals, tears are known to convey important messages: Male mice that cry attract females, and blind mole rats that weep ward off other males.
Perhaps human tears contained a chemical signal too, Sobel thought. So he asked six women to watch triple-hanky chick flicks such as "My Sister's Keeper" and let their tears trickle into a test tube.
Sobel had assumed the tears would trigger feelings of sadness or empathy. Instead, the tears dampened men's libido like a cold shower.
The 50 tear-sniffing men whose testosterone levels were tested experienced a drop averaging 13%. Sniffers who viewed erotic images before submitting to an MRI showed less activity in the sexual arousal regions of their brains, too.
The results imply that "tears have some influence on sexual selection, and that's not something we associate with sadness," said Adam Anderson, a University of Toronto psychologist who was not involved in the study. "It could be a way of warding off unwanted advances."