WASHINGTON — If a crying woman’s red nose isn’t a big enough turnoff to a man, a surprising experiment found another reason: Tears of sadness might temporarily lower his testosterone level.
Those tears send a chemical signal as the man gets close enough to sniff them — even though there is no discernible odor, say researchers from Israel’s Weizmann Institute of Science. It’s the first such signal to be found in tears, and it’s probably not unique to women’s. Theirs just were the first to be studied.
“It’s hard to get men to volunteer to cry” in a lab, said Weizmann neurobiologist Noam Sobel, senior author of the study appearing in today’s edition of the journal Science.
First, some women volunteered to watch a sad movie in the lab and collect their tears in a vial. For a comparison, researchers trickled saline down the women’s cheeks and collected those droplets too.
Healthy young men couldn’t smell a difference between the real tears and the sham ones.
Saliva tests of testosterone levels found a dip in that hormone after they sniffed tears but not the salt water. When they sniffed tears and then watched a sad movie inside a brain-scanning MRI machine, the men showed less activity in neural networks associated with sexual arousal.
Why would our tears have evolved a “chemosignal” to function as a sign of sexual disinterest? It’s possible that’s a proxy for lowering aggression, said Sobel, who now is trying to identify the molecule doing the work.
Stay tuned: He is now testing male tears, “as we finally have one good man crier.”
