Recent research published in PLOS Biology has revealed an intriguing facet of human tears—specifically, women’s tears—as a mediator of aggression in men. The study, conducted at the Weizmann Institute of Science in Israel, delved into the chemical impact of tears on male behavior, suggesting tears’ potential role in mitigating aggression.
Co-lead author Shani Agron, in her neurobiology doctoral research, investigated the chemical influence of tears on aggression reduction. The study observed that catching a whiff of women’s tears significantly decreased aggression in men, supported by human behavioral studies, brain imaging, and molecular biology.
Agron proposed that emotional tears in women might serve as a means to convey a chemical signal that diminishes aggression—a phenomenon potentially shared across various mammals, shedding light on a biological mechanism behind tear production.
Professor Noam Sobel, Agron’s advisor and co-senior author of the study, emphasized that tear shedding is not exclusive to humans, citing examples such as dogs shedding tears upon reuniting with owners and mice using tears’ molecular cues to influence social behavior.
The research builds upon earlier findings from 2011, where Sobel and his team demonstrated that women’s tears reduced testosterone levels and sexual arousal in men. This discovery led to a deeper exploration of tears’ effects on behavior, despite the challenges of collecting tears from donors.
The collection process posed difficulties due to the substantial amount of tears required for each participant—approximately one milliliter—far beyond what most volunteers could produce. Only a handful of men and six women among the volunteers could provide the necessary volume of tears, elicited through various emotional stimuli, including sad movies from the lab’s selection.
The study underscores the potential for tears, particularly women’s tears, to influence human behavior on a chemical level, despite the lack of a perceivable smell from tears in humans. This research opens new avenues for understanding the intricate connections between tears and social behavior in humans, mirroring similar mechanisms observed in other mammalian species.