Can Your Body Odor Be the Reason You're Friends with Someone?

By: Justin Shen

In an olfaction (smelling) lab, researchers have found out that people who had an instant friendship also had similar body odors.

All humans have their own odors. Although we are not constantly smelling each other, our body odors may affect how others act towards us.

On Wednesday, a small study was published in the journal Science Advances. Researchers examined the body odors of pairs of people who instantly became friends. They found that these people’s body odors were similar and not because of chance. To test this further, the researchers paired strangers to play a game. The body odors of the strangers reflected if they felt a good connection.

There can be many reasons why you become friends with someone new. This includes when and where you meet each other but scientists found that there can be other reasons too.

“If you think of the bouquet that is body odor, it’s 6,000 molecules at least,” Dr. Sobel said. “There are 6,000 that we know of already — it’s probably way more.”

Scientists have found out that not only can friends have similarities such as age or hobbies, but also in genetics, parts of brain activity, and appearance. Inbal Ravreby, who is an olfaction researcher at the Weizmann Institute of Science in Israel, thought that maybe instant friendships were linked with olfaction.

To find out if this was true, she recruited 20 pairs of instant friends. For a few days the people had to stop eating “odor changing foods” like onions and garlic and stopped using after-shave and deodorant. The lab also gave them unscented soap that they could use to bathe and a T-shirt they would wear to sleep to capture their body odor before they gave them back to the scientists.

Ms. Ravreby and other scientists found out that indeed, the body odors of the friends were similar, explaining one of the reasons their relationship began.

“It’s very probable that at least some of them were using perfumes when they met,” Ms. Ravreby speculated. “But it did not mask whatever they had in common.”

There was a problem though, the friends might have a similar smell because they might have gone to the same restaurants to eat and done other things together. Because of this, the scientists held another experiment. The researchers used 132 strangers that already slept with the T-shirt the lab provided and then went to the lab to play a mirror game. They were paired with a stranger and had to try copying what the other person was doing. After the game they would decide whether they felt a connection with their partner and fill out questions about it. The researchers found out that the strangers felt that connection 71 percent of the time.

Scientists still have much more to learn about our unique smells and what they could do. Just even a little bit of air might reveal something new.