5 New Findings About Why People Sniff Themselves

When in public, people typically want to look their best. To avoid embarrassing situations like having a large ketchup stain on our pants after eating a burger, we frequently check how we look by using mirrors and inspecting our clothes.

Self-Sniffing: A Common Behavior

But our visual appearance is not the only thing about ourselves we consistently monitor. Another highly relevant sense in social situations is scent. Smelling sweaty, rancid, or otherwise disgusting can have severe negative social consequences for people. Friends may not want to hang out anymore, or partners may end the relationship if the smell gets too bad.

Thus, it is not surprising that many people sometimes sniff at their bodies to check how they smell. Common examples are lifting the arm and sniffing the armpit to detect a sweaty smell or breathing into the hand to detect bad breath. Psychological research on self-sniffing has been rare in the past, so the psychological factors underlying self-sniffing are not well understood.

A New Study on Self-Sniffing

A new study recently published in the scientific journal Physiology & Behavior focused on the psychology of self-sniffing (or olfactory self-inspection, as the scientists called it) (Schwambergová and collaborators, 2023). The research team, led by scientist Dagmar Schwambergová from Charles University in Prague (Czech Republic), used an online questionnaire to determine many interesting facts about self-sniffing. Overall, 209 volunteers participated in the study. The volunteers filled out a questionnaire about self-sniffing and questions about hygiene and disgust.

The main insights from the study were the following:

1. The hands are the most commonly self-sniffed body part

The results of the self-sniffing questionnaire showed that hands were the most commonly sniffed body part, followed by armpits, hair, feet, and breath.

2. Worn T-shirts are the most common piece of clothing that people sniff

One way to sniff one’s body odor is to smell worn clothing items. Therefore, the scientists also asked the volunteers about this type of self-sniffing. Worn T-shirts were the most commonly smelled piece of worn clothing, followed by worn trousers, socks, and underwear.

3. There are three main types of self-sniffing

Using elaborate statistical methods, the scientists analyzed the volunteers’ answers regarding self-sniffing, identifying three main types:

1. Social acceptability self-sniffing: This type of self-sniffing includes sniffing worn clothes and body parts with a strong smell that others may notice, such as armpits and feet. To avoid negative reactions, these regions are frequently checked by some people.
2. Intimate self-sniffing: This type of self-sniffing includes the sniffing of body parts that people would typically not sniff in public due to social taboos (such as the navel).
3. Cosmetic self-sniffing: This type of self-sniffing includes sniffing body parts to which cosmetics (such as perfume or shampoo) are applied, such as the hair and the neck. People sniff these body parts to check whether the perfume still smells good.

4. Men and women sniff themselves differently

The scientists did not observe any gender differences in social acceptability self-sniffing. In contrast, men had a higher frequency than women for intimate self-sniffing, while women had a higher frequency than men for cosmetic self-sniffing.

5. People with health problems sniff themselves more often than healthy people

The scientists also found that people with more frequent health issues showed more social acceptability self-sniffing than very healthy people. This suggests that sick people check their smell more often to check for changes in smell due to illness.

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