The findings, in a study by the Weizmann Institute of Science and Wolfson Hospital near Tel Aviv on the role tears play in non-verbal communication, suggest that a chemical in women's tears lowers men's testosterone levels.
Researchers had expected the tears would boost the men's sense of empathy. Instead, their heart and respiratory rates, salivary testosterone and a brain scan all pointed to a reduction of sexual arousal.
The chemo-signal in women's tears, he said, was one way of saying "no, I am not interested."
Communication is key to survival. Humans, like all mammals, use smell in their communication. It is very efficient if you have a chemical signal which transmits what you want -- or clearly don't want -- in a sexual situation.