Study Reveals Humans Can Detect the Smell of Death Triggering Strange Behavior in Them
Human senses oftentimes react before brains have a chance to grasp the situation. Based on this unique ability possessed by senses, a 2015 study tried to understand if humans have a particular reaction to the 'smell of death,' IFL Science reported.
The researchers in the study wanted to find whether humans had a particular reaction to the smell, that typically comes from dead bodies. Their analysis concluded that humans do display out-of-ordinary behavioral mechanisms when confronted with putrescine (the chemical responsible for the smell that comes from rotting meat).
Human Reaction Toward 'Smell of Death'
Four experiments were done, to adjudge human reaction toward putrescine, IFL Science reported. The first setting analyzed the effect of putrescine on vigilance.
Participants were randomly assigned with a cotton wool pad dabbed with either putrescine, ammonia, or water. They were instructed to click on a red dot, after smelling the assigned chemical. Thereafter their reaction time toward the chemical was figured out, based on how much time they took to click on the dot. The next analysis was centered on escape behavior.
The participants were again randomly assigned the earlier set of chemicals and then instructed to walk for 80 meters. Their escape behavior was figured out based on how much time was taken to complete the walk.
Effect of Putrescine on Humans
In the third experiment, the participants were asked to do a word-stem completion task and then take a walk of 60 meters. This was done to examine the thoughts going on in their head after smelling particular chemicals.
The final experiment was about defensive behaviors and the effect of putrescine on humans even when undetectable. In this one, participants read an essay after being exposed to tiny concentrations of putrescine and ammonia and were told to finish a final questionnaire. The time they took to finish the final questionnaire, was used to examine their desire to escape.
Putrescine Test Results on Humans
Researchers found that even when putrescine was undetectable, participants were highly vigilant of the compound, IFL Science reported. The participants were walking faster, and were more quick with their responses while interacting with the 'smell of death.' The subjects associated with putrescine clicked on the red dot and completed the word stem, as well as the final questionnaire at a much faster pace, than the subjects who were assigned other chemicals. This implies that putrescine initiated a flight response in the senses of those subjects.
Researchers are yet to figure out what threat senses perceive from putrescine. "As a whole, the findings indicate that even brief exposure to putrescine mobilizes threat management responses designed to cope with environmental threats," concluded the authors. "These are the first results to show that a specific chemical compound (putrescine) can be processed as a threat signal." Researchers want further studies on the subject to figure out the exact nature of this threat.