We produce tears in response to insults to the eyes-the sting of onion
fumes, a tiny insect that flew into your cornea. But we also produce
emotional tears. And it's long been known that emotional tears are
chemically different from poke-in-the-eye tears. Now researchers at the
Weizmann Institute of Science in Israel find that women's emotional tears
have definite physiological effects on men. The work appears in the
journal Science. [Shani Gelstein et al, Human Tears Contain a Chemosignal]
The researchers knew that mouse tears contain pheromones that convey
information to other mice. So they looked for similar kinds of signals
in human tears.
Two women volunteered to watch sad movies and have their tears collected.
Twenty-four men were then asked to sniff the movie tears or a saline
solution. The men noted no particular smell in either sample of salty
water. But the men's own body chemistry could tell the difference.
When the men looked at emotionally neutral images of women's faces after
sniffing real tears, they reported less sexual attraction. The men also
had lower levels of testosterone and less physiological arousal after
smelling emotional tears compared with saline. Future studies will look
at men's tears, once researchers have collected enough videos of heartbreaking
losses in big football games.