It’s in our human nature to have the thought of death in our minds, and the way we depict death also connects with the scene of a dead animal, human, bird or flies. So, what’s the connection between all of them, but we didn’t think of it before? The smell.

According to recent studies, the human nose is capable to sense a wide range of smells, that cannot place them into any known category, but is still reacting to them. Such as the scent produced by a chemical called putrescine. This is a chemical that the body produces when it starts to decay, and one little thing to know, the scent is the result of the animal’s necrophobic behavior throughout the years of evolution, and these responses are thought to have evolved at least 420 million years ago.

The animals are thought that they react to the smell of putrescine as a sense of danger in a two different ways: the reaction that a predator is nearby, and the second is that they have been put in a life danger, so their instinct tells them to escape.

Scientists have made four different experiments on humans with a mixture of putrescine, water and ammonia, just to prove that human’s reactions and behavior are not any different than those of the animals.

Vigilance

The first experiment, where participants were tested to the scent of putrescine, as they were exposed to the scent of it and tested out their vigilance. The results showed that the participants who were exposed to the scent of putrescine showed more vigilance than those who were exposed to ammonia and water.

Escape behavior

The researches did the second test where they have tested unsuspecting group of people, who were given a task to rate a smell on it’s intensity, repugnance and familiarity. The researches wanted to see the group’s reaction to the smells, and how fast the participants would walk away at an 80m distance. Those who have smelled the putrescine, tended to walk away more quickly from the place, which proved that the smell evoked a strong motive to escape.

Escape-and-threat-related cognition

In another experiment, after the group being exposed to the scent of putrescine, the researchers gave the participants a word stem-completion task.

The results have shown that the smell of putrescine caused the group to complete the word stems, all realted with escape and other associations with the word escape. The smell also increased to use of thread words.

Defensiveness and hostility

The last experiment the participants were exposed to a very decent scent that they couldn’t detect. In this experiment, they were given a text to read, and the task was to evaluate the author of it.

They were not able to detect the subtle smell of the putrescine, the participants showed defensiveness and hostility to the author. This also proved that the non-conscious exposure to the smell evoked a defensive behavior in the participants.

Conclusion

The study proved that people are affected by the smell of putrescine, the chemical that’s released in a decaying body, both consciously and subconsciously. We are affected by it, we can detect it, smell it. And, most importantly, we react to it, as the smell of death, trying to escape it or avoid it. Maybe we consciously do not know it as the smell of decaying body, but our instincts work it out as the smell of death. Interesting, huh?