Dr. Noam Sobel: How Smells Influence Our Hormones, Health & Behavior | Huberman Lab Podcast

Tears & Testosterone

Human tears, particularly emotional ones, have a fascinating impact on testosterone levels and emotions. Noam Sobel explains that tears, while odorless, can lead to a significant reduction in testosterone levels when sniffed, particularly in men 1. This discovery emerged from experiments involving participants who could cry easily, revealing that emotional tears might serve as a chemical signal 2.

We found a few things. First of all, the tears are completely odorless. You cannot detect them at all. Completely odorless. And yet when you sniff them, you have a pronounced reduction in testosterone.

--- Noam Sobel

This intriguing effect highlights the potential of tears in non-verbal communication and social interactions.

   

Fear & Aggression

Odors play a significant role in modulating fear and aggression in humans. Andrew Huberman and Noam Sobel discuss how sweat, particularly from fear-inducing situations, is a common medium for studying human chemo-signaling 3. Sobel's lab has explored the effects of hexadecanal, a chemical signal, on aggression, finding that it reduces aggression in men but increases it in women 4.

Hexadecanal consistently reduced aggression. People were less aggressive under Hexadecanal. The effect size was quite meaningful.

--- Noam Sobel

This dual effect underscores the complexity of chemical signaling and its varied impact on human behavior.