Womens tears lower mens testosterone...

JOSEPH HALL

If women’s tears can make men melt, it’s because they’re meant to.

Israeli scientists have discovered that emotional tears shed by women have a hidden scent that lowers male testosterone levels significantly.

The scent may well be an evolutionary adaptation meant to protect women against aggressive or sexually charged men, says neurobiologist Noam Sobel, whose study was released Thursday by the journal Science.

“In our view this study opens a new field,” says Sobel, who studies biochemical signalling agents — often known as pheromones – that are secretly sent between humans.

So far, research on such subliminal substances has concentrated on human sweat, says Sobel, an assistant professor at Israel’s Weizmann Institute of Science.

“But sweat is not the only way humans emit chemicals, and that’s what led us to consider tears,” he says.

Earlier research had shown that tears shed from sadness or fear contained about 25 per cent more proteins than could be found in the eye-cleansing variety, produced when chopping onions or dusting furniture.

To see if these extra chemicals might be sending out signals, Sobel’s team recruited a contingent of six readily weeping women.

“Each one of these women has their own favourite tear-jerking film,” says Sobel, senior author on the three-year study. “And they sit down in a room on their own with the video film and a vial.”

These tears were then whisked off to be smelled, fresh, by any of the study’s 50 male subjects. Half the time the males were given ordinary saline water to sniff, while the other half they were presented with the tears.

The men, who were not told which liquid they were smelling, could identify no apparent odour difference between the two. But when sniffing the emotional eye effluence, they showed a number of marked physiological and psychological changes.

In one experiment, men viewing images of women’s faces found them less sexually attractive when they had smelled the tears than they did when presented with the saline solution.

As well, men reported being less sexually aroused in general after whiffing tears than they did when the salt water was used.

“But what told a more pronounced story were the physiological measures,” Sobel says. “Tears reduced testosterone compared to saline very significantly.”

Measured in saliva samples, testosterone levels were lower in 40 of the 50 men after sniffing the tears than they were with the inert saline water.

Sobel does not know yet what the active tear chemicals are, or where or how they are produced in the body.

And the study could not say whether male tears have the same calming effect. When researchers advertised for crying recruits, there simply were no male takers, Sobel says.

“We posted an ad looking for individuals who could cry with ease and we obtained an overwhelming reply from women volunteers and absolutely no men.”