Does your nose help you choose your friends?

Humans maintain the polite fantasy that we don’t constantly smell each other. Despite our efforts to the contrary, we all have our own scents, nice and understated, and If we are like other land mammalsOur own perfume It might mean something to our fellow human beings.

Some of these things, like the smell of someone who hasn’t bathed for a month, or the characteristic whiff of a toddler pretending not to just fill his diaper, are self-explanatory. But scientists who study human smell, or your sense of smell, wonder if molecules escaping from our skin might register on a subconscious level in the noses and brains of the people around us. Do they carry messages that we use to make decisions without even realizing it? Can they even shape who we do that we don’t like spending time around?

In fact, in A small study was published Wednesday in the journal Science AdvancesResearchers who investigated pairs of friends whose friendship “clicked” from the start found intriguing evidence that each person’s body odor was closer to their friends’ scent than expected by chance. And when the researchers got pairs of strangers to play a game together, their body odors predicted whether they felt they had a good relationship.

There are many factors that determine who people become friends with, including how, when, and where we meet someone new. But the researchers suggest that one thing we might catch is how they smell.

Scientists who study friendship have found that friends have more in common than strangers — not only things like age and hobbies, but also GeneticsAnd the brain activity patterns and appearance. Inbal Raffrebi, a graduate student in the lab of Noam Sobel, an olfactory researcher at the Weizmann Institute of Science in Israel, was curious whether particularly fast friendships, the kind that seem to form in an instant, contain an olfactory component — could they for people to do that? They pick up similarities in their scents.

She recruited 20 pairs of so-called friends, both of whom characterized their friendship in this way. Next, I put them into a regimen common in human body odor research: stop eating foods like onions and garlic, which affect body odor, for a few days. Get rid of deodorant after shaving. Bathe with unscented, lab-provided soap. Then put on a new, clean, lab-fitted T-shirt and sleep in it until it’s good and smells good, before handing it over to scientists for review.

Ms. Raffreby and her colleagues used Electronic nose To assess volatiles rising from each shirt, they had 25 other volunteers assess the similarity of smells as well. They were interested in discovering that friends’ scents were indeed more similar to each other than to strangers’ scents. It could mean that the smell was one of the things they picked up when their relationship started.

“It is very likely that at least some of them used perfume when they met,” Ms Raffreby speculated. “But she did not hide everything they had in common.”

However, there are many reasons why friends smell alike – eating at the same restaurants, following a similar lifestyle etc. – which makes it difficult to determine whether the smell or the basis of the relationship comes first. To verify this, the researchers had 132 strangers, all of whom stained a T-shirt first, came to the lab to play a game of reflection. Pairs of subjects stood close together and had to imitate each other’s movements as they moved. Next, they filled out questionnaires about whether they felt connected to their partners.

Strikingly, the similarities between their scents predicted whether they both felt a positive connection 71 percent of the time. This finding indicates that smelling a scent similar to ours generates good feelings. It might be one of the things we pick up on when we meet new people, along with things like where they grew up and whether they prefer science fiction or sports. But Dr. Sobel cautions that if that’s the case, it’s just one factor among many.

The Covid pandemic has so far slashed further research using this design by Ms. Raffreby and her colleagues; It was difficult to conduct experiments in which strangers got close enough to smell each other.

But now, the team is looking at modifying people’s body odor to see if people who were sniffed with a similar scent stick together. If smell is associated with their behaviour, this is further evidence that, like other terrestrial mammals, we may rely on our sense of smell to help us make decisions.

There are many mysteries for them and other researchers to study how our personal fragrances, in all their intricacies, interact with our personal lives. Each puff of air may say more than you know.

“If you think about the bouquet that is body odor, it’s at least 6000 molecules,” Dr. Sobel said. “There are 6000 we already know – probably a lot more.”