You have probably seen more than once how some mammals, for example, dogs or cats, carefully sniff each other when they meet. Why do they do it? It’s simple: to identify who is in front of them – friend or foe.

For us, the smell of another person can also matter more than it seems at first glance. So, a recent study conducted by the staff of the Weizmann Institute in Rehovot (Israel) proved that people have a subconscious sympathy for those whose natural smell resembles their own. The results were published in the journal Science Advances.

Smell and Friendship

Scientists proceeded from the fact that we usually tend to be friends with those who are similar to us in origin, appearance and value system.

“Because people seek friends who are similar to themselves, we hypothesized that people can smell themselves and others in order to subconsciously assess the similarity of body odors, which in turn may promote friendship,” the authors say.

To confirm this assumption, the researchers recruited a team of volunteers, which included same-sex couples of friends (we were not talking about sexual partnerships, only friendships), the relationship between which, according to surveys, formed very quickly, literally from the first meeting. A control group was also involved, the members of which were not friends with each other.

Samples of their body odor were taken from all participants. To do this, they wore T-shirts for a certain time, which were then transferred to scientists.

Experiments on “mirroring”

The first series of experiments used a device known as the electronic nose, or eNose. It was equipped with ten metal oxide sensors, coated with different materials, designed to respond to different chemicals.

In the next step, a group of volunteers from the outside were asked to smell the samples in order to evaluate the similarities and differences between them. The samples were presented in pairs.

It turned out that both the electronic device and the human volunteers equally perceived the similarity between the smells of the samples obtained from friendly couples. In random pairs, this percentage was significantly lower.

To ascertain the results, the experts tried to exclude concomitant causes. For example, there was a possibility that friends had a similar body odor because they influenced each other in some way. Let’s say they eat the same food or lead a similar lifestyle.

For this, an additional series of experiments was carried out. First, several unfamiliar volunteers were “sniffed” by the device. Then they were divided into pairs for a game of “Mirror”. It consisted of the fact that the participants were placed facing each other at a distance of at least two feet and asked to “mirror” the movements of the hands of a partner in the game.

After each such “mirroring session,” the subjects had to rate their “companion” in terms of how much they like him and what is the likelihood that they could become friends. As a result, the researchers concluded that if the participant perceived the second player as a potential friend, then their smells turned out to be similar.

It’s all about the template!

The computational model built by the scientists was able to predict with 71% accuracy which couples would like each other using eNose data. Therefore, the hypothesis that body odor contains information that determines the quality of social interactions between people is most likely correct.

According to the head of the study Inbala Ravrebiwe tend to form in our subconscious a certain “template” associated with our own smell, and compare the smells of others with it.

“Previous research does support the idea that self-referential processing can mediate body odor identification in humans, as it does in other primates,” he said.

Zhanna Gladkova: We always follow the smell