Women's tears as an antidote to male aggression? New study reveals surprising connection
Tears serve more than just the purpose of moisturizing and cleaning our eyes. Emotions such as sadness, joy, anger, or being moved can trigger crying. Yet, why humans developed this capability is still unclear. Previous studies have demonstrated that mammalian tears contain chemical substances that work as social signals, which can be emitted on demand. On the heels of this insight, researchers decided to investigate if this extends to humans, focusing their study on men.
A simple study with surprising conclusions
Male participants in the study were given either women's tears or a saline solution to sniff, neither of which possesses any inherent scent. Following this, they engaged in a two-player game, designed with the purpose of inducing aggressive behavior. Tactics included suggesting that the other player was cheating and could be retaliated against. Surprisingly, men who had smelled women's tears displayed approximately 44 percent less aggression than those who had sniffed the saline solution.
The research team thoroughly studied the men's olfactory receptors and discovered that four of them were activated by tears. MRI scans of men inhaling the scent of tears depicted that two brain regions linked with aggression – the prefrontal cortex and the anterior insula – didn't show increased activity when the men were provoked during the game. Similarly, chemical substances found in rat's tears, known to inhibit male aggression, were also present. This could potentially challenge the belief that only humans cry due to emotions.
What is it about women's tears that makes men less aggressive?
Scientists suspect that the tears from any gender would have a similar affect. However, due to societal influences, women's tears generally contain less testosterone and as the testosterone level decreases, it's observed that aggression also reduces, a phenomenon particularly noticeable in men. According to these scientists, tears primarily help children defend themselves against aggression. It's highlighted that infants and small children, having no alternative way to express their emotions, rely on tears as their only means of protection against potential aggressive behavior.
"Crying often happens in intimate interactions to the extent that 'kissing tear-streaked cheeks' is a recurring theme across cultures. Hence, chemosensation of tears emerges as a highly probable solution. This is particularly relevant in the case of infant tears, as infants, lacking verbal communication means to ward off aggression, often rely on chemosignals," reads the research paper, which was published in PLoS Biology.
