The research, published on Thursday in the journal Science, could begin to explain something that has baffled scientists for generations: Why do humans, unlike seemingly any other species, cry emotional tears?

In several experiments, researchers found that men who sniffed drops of women’s emotional tears became less sexually aroused than when they sniffed a neutral saline solution that had been dribbled down women’s cheeks. While the studies were not large, the findings showed up in a variety of ways, including testosterone levels, skin responses, brain imaging and the men’s descriptions of their arousal.

“Chemical signaling is a form of language,” said one of the researchers, Dr. Noam Sobel, a professor of neurobiology at the Weizmann Institute in Israel. “Basically what we’ve found is the chemo-signaling word for ‘no’ — or at least ‘not now.’ ”