Scent of a Friend?

Science Fun Fact-- December 20, 2022:It has been discovered by scientists at the Weizmann Institute of Science that people may be more likely to

become friends with others who have a similar body odor.

Researchers were also successful in predicting the quality of social interactions between total strangers by "smelling" them with an electronic nose, or eNose. The findings, published

in Science Advances, hint at a potential bigger function for human smell in social interactions than was previously recognized.

Every dog owner knows their pooch can typically determine from a distance if another dog is friend or foe. Upon meeting, if the two dogs are on the fence about whether to play nice or go to war, they may take a good, long sniff of each other to settle the matter. In all terrestrial mammals outside humans, the sense of smell has been shown to have a preponderant role in social interactions. Is it because humans don't rely on their noses to communicate with others? Do humans engage in this sort of thing, or does it remain hidden?

Inbal Ravreby, a graduate student in the Brain Sciences Department at Weizmann, postulated the latter to be the case while working in the lab of Prof. Noam Sobel. She based her conclusion on a pair of earlier findings. A number of indicators point to the fact that people are always, however unconsciously, sniffing themselves. The second reason is that it's common for people to unconsciously take a whiff of those around them. Friendships are formed with those who are similar to oneself in terms of personality, upbringing, ideals, and even neuro-cognitive functioning. The idea put up by Ravreby is that when people sniff themselves and others, they may be making unconscious comparisons and gravitating toward others whose smell is similar to their own.

Ravreby found "click friends,"  same-sex friends who aren't romantically involved with one other, to test her theory. She conjectured that body odor and other physiological characteristics would have a disproportionate impact on the formation of such friendships since they occur before a more in-depth acquaintanceship has taken place. She then conducted two sets of tests in which she compared body odor samples acquired from these click pals with those collected from random pairings of persons. She used eNose, a device that analyzes chemical odor signatures, to do the comparison in one set of studies. In the latter, she used human perception to compare the two sets of body odor samples. It was discovered in both trials that those paired together through click friendships smelled more similar to each other than those paired at random.

Ravreby next wanted to disprove the idea that the resemblance in body odor was an accidental byproduct of click friendships. What if, for instance, the friends shared a common odor because they ate the same kinds of food or went through the same kinds of events that contribute to one's body odor? To investigate this, Ravreby undertook a second set of tests in which she had a group of strangers participate in nonverbal social interactions with one another after she had "smelled" them using an eNose. Participants assessed the other person's likeability and potential for friendship after each such structured contact. After further investigation, it was found that those who had better rapport actually shared a more similar scent profile (as measured by the eNose).
In fact, Ravreby and statistician Dr. Kobi Snitz were able to predict with 71% accuracy which pairs of people will have a favorable social contact by entering eNose data into a statistical model. To rephrase, it seems that a person's body odor can provide clues about the quality of their future interactions with complete strangers.

"These results imply that, as the saying goes, there is chemistry in social chemistry," Ravreby concludes. Sobel offers words of caution: "This is not to say that we act like goats or shrews -- humans likely rely on other, far more dominant cues in their social decision-making. Nevertheless, our study's results do suggest that our nose plays a bigger role than previously thought in our choice of friends."
Prof. Noam Sobel is head of the Azrieli National Institute for Human Brain Imaging and Research; his research is supported by the Sagol Weizmann-MIT Bridge Program; the Rob and Cheryl McEwen Fund for Brain Research; and Miel de Botton. Prof. Sobel is the incumbent of the Sara and Michael Sela Professorial Chair of Neurobiology.
 
Weizmann Institute of Science, is the source of information, "Scent of a friend: Similarities in body odor may contribute to social bonding: An electronic nose relying on body odor chemistry may predict whether we are likely to 'click' with a stranger." ScienceDaily. ScienceDaily, 27 June 2022. .

WNCTIMES by Marjorie Farrington