Cry baby

Emotional crying is uniquely human. I had never thought about it, but it’s true. In this month’s issue of Science Express scientists reveal that many of the tears we shed are chemically encoded. For instance, one whiff of a woman’s tears and men are left cold, as in reduced sexual response.

It’s no secret humans expel all kinds of compounds in our body fluids, sweat, tears, etc. Sweat for instance is greatly encoded with information about our state of mind, sexual interest, fear level and stress experience. Since tears seem to be odorless, no one thought about whether or not they would have the same effect.

Until Shani Gelstein, Yaara Yeshurun and other colleagues in the lab of Prof. Noam Sobel in the Weizmann Institute’s Neurobiology Department started wondering. They got tear samples from women who watched sad movies to produce them. They asked men if they could tell the difference between the tears and saline. They could not.

Phase two of the experiment, they asked men to sniff then evaluate picture of women. They did this for several days. Surprise, sniffing tears lead to a negative reaction to women and a reduced sexual appeal. They confirmed these finding with MRI studies as well.

Sobel said, “This study raises many interesting questions. What is the chemical involved? Do different kinds of emotional situations send different tear-encoded signals? Are women’s tears different from, say, men’s tears? Children’s tears? This study reinforces the idea that human chemical signals – even ones we’re not conscious of – affect the behavior of others.”

Source: Weizmann Institute of Science, ScienceDaily