Women’s tears contain chemicals that block male aggression, a study by Israeli scientists found, cited by the electronic edition “Euricalert”.
Specialists from the Weizmann Institute of Science found that tears lead to a reduction in brain activity associated with aggression, which in turn limits such behavior in the representatives of the stronger sex. The effect occurs after men “smell” the tears.
Male aggression in rodents is known to be blocked when they smell the tears of female specimens. This is an example of social chemosignaling, a process that is common in animals but less common—or less well understood—in humans. To see if they have the same effect in humans, the researchers observed the impact of female emotional tears on a group of men who participated in a special game for two. For the purposes of the analysis, some of the volunteers were given saline instead of tears.
The game is designed to provoke aggressive behavior against an opponent perceived to be cheating. When given the opportunity, men can retaliate against a competitor by making him lose money. The representatives of the stronger sex do not know what they are smelling and cannot distinguish between tears and saline, which are odorless.
Aggressive behavior aimed at revenge during a game dropped by more than 40% after men had access to women’s emotional tears, according to Israeli data.
In the re-examination with magnetic resonance imaging, functional imaging showed two brain regions associated with aggression – the prefrontal cortex and the anterior insula. They are activated when men are provoked during the game, but they are not activated as much in the same situations when the representatives of the stronger sex are under the influence of tears. Moreover, it is clear that the greater the difference in this brain activity, the less often the opponent retaliates during the game.
The discovery of this link between tears, brain activity and aggressive behavior suggests that social chemosignaling is a factor in human aggression rather than just animal curiosity.
“We found that, just like in mice, human tears emit a chemical signal that blocks male aggression. This contradicts the notion that emotional tears are uniquely human,” noted the Israeli scientists, led by Shani Agron.
The research data is published in the open access journal PLOS Biology
