Friends on the first sniff: people attracted to others who smell like them

People who click right away are often said to share “chemistry”.

This expression could be true in the literal sense, according to a new study published in the journal Scientists progress Friday, which reveals that people with similar body odors are more likely to get along like friends.

“Non-human terrestrial mammals constantly sniff each other and, based on this, decide who is friend or enemy,” wrote a group of researchers led by Inbal Ravreby at the Weizmann Institute of Science in Israel.

Since people seek out friends who look like them, the team hypothesized that humans can smell themselves and others to subconsciously estimate body odor similarity and judge compatibility.

To find out, they set about collecting samples from pairs of same-sex, non-romantic friends who described themselves as having clicked at first sight, i.e. “where a sense of friendship was formed before much biographical information was exchanged”. depending on the paper.

After an extensive recruitment effort, they found 20 couples, half of whom were male and the other half female, all between the ages of 22 and 39.

In order to avoid any contamination or outside factors influencing their samples, all participants were required to follow a strict protocol which included avoiding pungent foods and sleeping away from their partner and pets in a clean cotton t-shirt that was provided to them.

The t-shirts were collected in ziplock bags and tested with an electronic nose, a device equipped with sensors to analyze chemical composition. The researchers found that the olfactory signatures of “click friends” were statistically closer than the odors between non-friends.

To assess whether eNose results accurately reflect human perceptionthe team recruited human smellers and designed a series of tests to check the validity of their result.

In one such test, for example, three odors were presented to human moods: two from a pair of clickbuddy and one aberrant. They managed to identify the pairs and reject the outlier.

Also feel the predicted friendships

These results seemed to confirm the hypothesis that similar smells could stimulate friendship, but another explanation was that people who are friends spend a lot of time together and therefore have similar bodies.odour shape experiences, like where they live and what they eat.

To disentangle these two possibilities, the team devised another test to see if smell could be an effective predictor of whether two people who have never met continue to click.

They recruited 17 strangers and had them all interact with each other in a test called the “Mirror Game” – standing half a meter apart so they could subconsciously feel each other, they were asked to imitate each other’s hand movements for two minutes, without speaking to each other.

The chemical similarity of their odors, as tested by the eNose, successfully predicted mutual clicks in 77% of cases and predicted 68% of cases where both sides reported not clicking.

Additionally, the closer people smelled, the more they reported liking, understanding, and feeling greater chemistry with each other.

Together, the study results “converged to suggest that same-sex human non-romantic click friends feel more similar to each other than expected by chance,” the team concluded.

Humans, unlike other terrestrial mammals, use a complex language to interact, and so it’s possible the effects of the scent in the lab were magnified relative to their significance in real life, the team wrote.

“Nevertheless, we think our results imply that we may also be more like other terrestrial mammals in this regard than we generally appreciate.”

© 2022 AFP