When exposed to the smell of a single molecule found in blood, predator and prey had very different reactions.
To see how humans would react to E2D, Lundström and Arshamian rounded up 40 male and female college students. When E2D was pumped through tubes into the students’ nostrils, they tended to move backward by a fraction of a millimeter, which the researchers say is a common sign of aversion. They also secreted more sweat than when exposed to the control.
In a study published in the journal Chemical Senses, Herz found that people are most sensitive to smells in the early and mid-evening. This adaptation could help warn people of the presence of predators when visibility begins to diminish.
In the next iteration of their experiment, Lundström hopes to test E2D on human participants separated by profession and age. He theorizes that people who regularly come in contact with blood, such as surgeons or hunters, may have different responses from those who rarely encounter it. Similarly, he hopes to see if response to E2D changes with age and other life experiences.
Source: Why the Scent of Blood Lures Wolves But Repels People
