Emotional signals are chemically encoded in tears, researchers find

Emotional crying is a universal, uniquely human behavior. When we cry, we clearly send all sorts of emotional signals. Scientists have demonstrated that some of these signals are chemically encoded in the tears themselves. Specifically, they found that merely sniffing a woman's tears -- even when the crying woman is not present -- reduces sexual arousal in men.

http://www.sciencedaily.com/releases/2011/01/110106144741.htm