Issue Date: January 10, 2011
Sad Tears Carry Chemical Signals
Human tears carry more than just emotional baggage, according to a study. They also carry chemical signals that can influence the behavior of other individuals. Only humans are thought to shed tears as a result of their emotions, whether happy or sad. Intrigued that the chemical makeup of such emotional tears is different from that of tears generated reflexively to protect the eye, Noam Sobel of Israel’s Weizmann Institute of Science and colleagues wondered whether emotional tears might play a signaling role in humans. They collected the tears of women who watched sad movies and found that men who sniffed these tears were less likely than those who sniffed vials of saline to consider women in photographs sexually attractive (Science, DOI: 10.1126/science.1198331). The men who sniffed the tears also experienced a drop in physiological measures of arousal and testosterone levels. And sniffing the tears reduced activity in brain regions tied to sexual arousal, as measured by functional magnetic resonance imaging. The researchers are now trying to isolate the relevant signaling molecules from the complex mix of proteins, enzymes, lipids, metabolites, electrolytes, and drugs that are in human tears.
- Chemical & Engineering News
- ISSN 0009-2347
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