by Honoreé Brewton
The human nose has the ability to smell over one trillion (1,000,000,000,000) scents. What’s your favorite smell? Is it the scent of old books in the library? Or the earthy smell after it rains that is called “petrichor”? How about the smell of your best friend?
It might sound a bit strange, but you may choose your friends based on how closely they smell like you. Earlier this year, a team of researchers explored the idea behind the phrase, “there is chemistry between us,” and hypothesized that humans may use their sense of smell to determine the bond they have with others. Let’s go over what the researchers found in their study.
The researchers recruited 20 pairs of same-sex friends who claimed to have a “click friendship,” which was defined by the study as a “good friendship that is rapidly formed.” Each participant was instructed to wear the same cotton t-shirt provided to them for two nights while sleeping. During this time, they were also told to avoid foods (such as garlic and curry) and beauty products (such as lotions, deodorants, and perfumes) that could influence body odor. After the shirts were returned, researchers used both machine and human ratings to determine the similarities and differences between the scents present on the shirts.
Researchers utilized an electronic nose, or “eNose,” which is a device that contains sensors capable of assessing the chemical compounds associated with an odor. The eNose sensors found that the chemical makeup of click-paired shirts was significantly more similar than the chemical makeup of randomly paired shirts. To put it simply, the shirts from click friends smelled more similar than randomly paired shirts. Although it is interesting that the machine was able to make this discovery, the researchers also wanted to confirm this result with human “smellers.” Twenty-four smellers rated the smell of the t-shirts based on factors including their intensity, pleasantness, and warmth (in terms of personality). The smellers also identified similar-smelling shirts by choosing which shirt out of a group of three was the outlier (as in the one that smelled the most different).
In addition to assessing the smells of people who were already friends, the researchers wanted to study the smells of strangers and the social interactions between pairings of strangers. The researchers paired up same-sex strangers and measured the ability of the pairs to mirror each other’s movements for 2 minutes. Afterward, the participants rated how closely their movements overlapped with that of their partner. They also identified whether or not they “clicked” with their partner. The pairs who reported clicking with their partner had more similar smells (as decided by the eNose) than the pairs who had not reported clicking.
I bet that right now, you’re thinking about whether or not you smell similar to your friends. It’s okay if you do! Based on the results of this study, the researchers believe that body odor similarity may lead us to become faster friends. Part of the human experience is finding people who share similar interests, so feel free to use your nose and take a whiff of those around you. However, maybe not too closely, as personal boundaries should still be respected.
