Research shows that sniffing women’s tears reduces aggressive behavior in men

New research, published in Biology PLOS, shows that women’s tears contain chemicals that block aggression in men. The study led by Shani Agron of the Weizmann Institute of Science, Israel, finds that sniffing tears leads to a reduction in aggression-related brain activity, leading to less aggressive behavior.

It is known that male aggression in rodents is blocked when they smell female tears. This is an example of social chemosignaling, a process common in animals but less common – or less understood – in humans.

To determine whether tears have the same effect in people, researchers exposed a group of men to women’s emotional tears or a saline solution while they played a two-person game. The game was designed to elicit aggressive behavior towards the other player, who the men were led to believe was cheating.

When given the opportunity, men could take revenge on the other player by making him lose money. The men didn’t know what they were sniffing and couldn’t distinguish between tears and saline, both of which were odorless.

Aggressive, revenge-seeking behavior during the match dropped by more than 40% after men sniffed out women’s emotional tears. When repeated in an MRI scanner, functional imaging showed two brain regions linked to aggression – the prefrontal cortex and the anterior insula – that became more active when the men were provoked during play, but did not become as active in the same situations when men. let’s sniff back the tears.

Individually, the greater the difference in this brain activity, the less the player retaliates during the game. Finding this link between tears, brain activity and aggressive behavior implies that social signaling is a driver of human aggression, not just animal curiosity.

The authors add: “We discovered that, just like in mice, human tears contain a chemical signal that blocks aggression from male peers. This goes against the idea that emotional tears are uniquely human. »