Chemicals produced by humans, such as those in tears, on skin, and in sweat and breath, can powerfully modulate the biology and internal state of other individuals.

“humans are making molecules, typically odors, and communicating those to one another to powerfully impact their testosterone levels, their vasopressin levels, their immune molecules.”

“But what is absolutely clear, what is undeniable is that there are chemicals that human beings make and release in things like tears onto our skin and sweat and even breath that powerfully modulate or control the biology of other individuals.”