Have you ever had this experience? After you have been in the same environment with someone for a period of time, you suddenly have a crush on him/her. Even if you don’t like him/her, you will feel that the other person is a like-minded person. people.
Some people will judge this situation as love at first sight, and they may "see" the other person. But according to new research in Science Advances, the strange feeling of may not come from your eyes, but from produced by your nose.
Research has found that the thrill caused by smell does not only occur between people of the opposite sex. Friends of the same sex may also be attracted together because of smell and become close partners.
In fact, this behavior of relying on the nose to judge social level is not uncommon among mammals. Many animals will use the sense of smell to understand whether the other party is a companion who can play, or is an attack target that needs to be alert, or needs to be avoided immediately. Predator.
However, the role of the human sense of smell is often ignored. Studies have pointed out that in human social behavior, smelling each other sounds like a behavior that violates social etiquette. Therefore, it is generally believed that the sense of smell plays little role in human sociality.
Image source: 123RF
In order to verify the importance of smell in human relationships, Israeli scientists recruited 20 pairs of close friends of the same gender, who all felt a special sense of intimacy when they saw each other.
These participants will then be asked to wear a brand new T-shirt when sleeping. Of course, they need to take a bath with unscented soap before going to bed, and they are not allowed to eat strong-smelling food.
After researchers wear a T-shirt to sleep for 6 hours, the T-shirt will be sent to an odor analysis device PEN3 eNose, which has a gas storage and odor sensing unit. With the help of supporting analysis technology, researchers can analyze the similarity of various molecular compositions between odors.
▲The smell of T-shirts was collected through equipment, and the study found that the odor molecular composition of close partners is similar (Picture source: Reference [2])
In addition to machine recognition, there are another 25 volunteers who act as human analysts. Identify the two odor sensations given by the researcher, which may come from close partners or may be randomly matched.
Whether it is a machine or a human volunteer, can invariably identify the smell similarity of close partners' T-shirts, while the randomly matched T-shirts have obviously different smells.
In addition, volunteers also need to rate 40 smell samples based on the pleasantness of the smell, sexual attraction, personality feelings, etc. The results are clear, 's two scent scores from close partners are very similar to 's, while if it is someone else, the scores will be somewhat different.
This also shows that different smells bring very different feelings to strangers, but if two people are very good friends, then other people's olfactory feelings towards them should be very similar.
Knowing this, researchers want to know whether it is possible for strangers to use smell to enhance their sense of closeness. So they recruited a new group of volunteers they didn't know at all. These volunteers were paired up in pairs and required to imitate each other's movements without being able to make sounds.
▲Two strangers feel that they are in tune with each other, and their odor molecular composition is largely similar (picture source: reference [2])
After the entire test game is over, 1/3 of the matching combinations indicate that they They have a special fondness for each other. Likewise, these people showed a high degree of similarity in their odor chemical molecules, which was not the case for those who were indifferent to each other.
Researchers said that relied on the compositional similarity of odor molecules to predict whether the two people could cooperate with each other with an accuracy of 71%.
Some past studies have found that when humans smell the smell of a stranger, the amygdala responsible for fear and alertness is activated . In contrast, when people smelled a friend's scent, the amygdala was not activated.
This may explain to a certain extent why people feel a sense of distance when the smell is inappropriate.
However, the new study also unexpectedly found that if researchers asked volunteers to compare three smells at the same time (2 from a pair of close partners and 1 from another person), they would not be able to judge the relationship between the smell owners. .
This is probably the charm of the light bulb...
Reference:
[1] Friends Who 'Click' Have Something Peculiar in Common: Their Smell. Retrieved June 27, 2022 from https://www.sciencealert.com/friends- who-click-smell-similar
[2] There is chemistry in social chemistry. Science Advance (2022). DOI: 10.1126/sciadv.abn0154
