We were talking about tears as a unique human signal that are hypothesized to elicit empathy the other day (please someone, I would love a source on this, so I can stop bullshitting based on a vague memory of having read this somewhere potentially apocryphal), & it turns out they are effective even in the absence of the faces they are running down. When they are removed from the face & (without even the accompanying snot even) placed under the noses of male test subjects, arousal & testosterone levels in those males dropped! This from a short piece by Sarah Everts called "Sweat & Tears" in the March 2012 Smithsonian based on work from the Sobel lab, published in Science 2011, Issue 331 Vol 6014 ("Human Tears Contain a Chemosignal").
Other interesting tidbits from the Smithsonian piece:
- The pheromones in boars that are sublimely effective are androstenon & androstenol, & they're in the saliva (yum).
- A 2005 study found gay men prefer the smell of gay men, & heterosexual men prefer the smell of women.
- We all know about the classic smelly t-shirt contest & MHC compatibility.
- Newborn babies like the smell of boobs! No one knows what the chemicals are yet because they're busy sniffing armpits, not breast milk.
- We can tell if someone is anxious by the smell of sweat (in reflecting, yes, perhaps, but I'm thinking that, yes, my sweat is different when I'm nervous--I'm not sure I've ever sniffed Uruk-style & said, "I smell anxious man-flesh").