Fear, that is. A study out of Stony Brook University in New York State has found that people can unconsciously detect stress of fear in others by smelling a chemical pheromone released in sweat.
Dr Lillianne Mujica-Parodi and her team enlisted 20 first-time skydivers to aid them in their research. Strapping absorbent pads to the participants armpits, the team collected the sweat from before and during the jump. As a control, sweat was also collected as the participants ran on a treadmill for the same length of time and at the same time of day as the jump.
The sweat was then mixed with air and given to volunteers to breathe in (yuck!). At the same time their brains were scanned, and the results showed that the amygdala and hypothalamus, which are brain regions associated with fear, were more active in people who breathed in sweat from the skydive. They weren’t able to actively distinguish between the two types of sweat, however. Mujica-Parodi wrote in a conference presentation last year:
“We demonstrate here the first direct evidence for a human alarm pheromone … Our findings indicate that there may be a hidden biological component to human social dynamics, in which emotional stress is, quite literally, ‘contagious’.”
She could not give any further comment however, as the study is currently under peer-review for publication in a scientific journal.
The research was funded by the US Defence Advanced Research Projects Agency, suggesting a possible military application, perhaps causing fear in enemy troops. DARPA has denied any such plans, and says it will not be funding further research in the field.