New research explores whether humans can detect unconscious messages from chemosignals in body odors. Can these faint signals really tell us what other people are feeling? Can humans actually smell emotions? The answer may surprise you.
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Do Emotions Have an Odor?
We’ve all heard the saying that animals can smell fear. Depending on the breed, a dog has up to 250 million smell receptors compared to the average person with only a paltry 5 million.
Also, we’ve all heard about pheromones, which are highly used in the animal kingdom. Supposedly, humans can unconsciously detect these and experience a reaction, such as being attracted to a mate.
Surprising Findings in Multiple Studies
A study published by the National Institutes of Health (NIH) in 2013 concluded: “Human and complementary studies in non-human animals provide evidence that odors evoke emotion and autonomic state via pathways to the amygdala and OFC, and become incorporated into episodic memory via the hippocampus.”
In recent years, researchers have been exploring whether there is an intraspecific (within species) and interspecific (between species) communication and detection of emotions involving humans.
Another study published by NIH in May 2020 concluded that emotions are transmitted by humans and perceived by humans and animals alike.
“Chemosignals derived from axillary odors collected under a variety of emotional stimuli and sad tears in humans affect receivers’ social interactions, danger detection, and risk‐taking behavior, social aspects of eating, and performance under stressing conditions,” the study found. “In addition, beyond the fight‐or‐flight response, even the body odors of happiness can be perceived by others. Furthermore, human chemosignals can influence behaviors and stressful responses in animals, particularly dogs and horses, which may partially explain their special relationship with humans.”
The study concluded: “Our review highlights the importance of chemosignaling in human intra‐ and interspecific interactions and suggests the need for further investigation…”
Emotional Odors Affect the Behavior of Others
Some of the most surprising findings indicating that humans can smell emotions come from a 2023 study by European researchers. The study concluded that humans can detect the scent of fear and anxiety in other people. Others can detect emotion-related changes in body odor. Humans sometimes respond to emotional body odors. They might be influenced by unconscious messages that are sent through these chemosignals. These changes can also induce physiological responses and affect behavior.
In addition, other studies concluded that humans can smell disgust and fear and that these emotions are contagious. For example, stress chemosignals can be transferred via body odors, impacting the emotional behavior of depressed individuals.
Researchers say that if we were chatting with someone who was feeling happy, we would likely smell that emotion and detect their current emotional state through our noses. An experiment conducted in the Netherlands tested this by having volunteers watch cheerful videos while holding absorbent pads under their armpits. Later, another group sniffed the pads. Measurements of their facial muscles revealed that their smile muscles moved more, and their mood improved.
A 2020 study found that women’s brains reacted more strongly when they smelled the sweat of men who played an aggressively competitive game. On picking up these odors, the women became more risk-avoidant and less trusting.
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Odors Affect our Social Life
The results of numerous studies seem to suggest that people with more sensitive noses have a more enhanced social life. This is backed up by functional magnetic resonance imaging of the brain, which reveals that the same brain circuits may be involved in both our sense of smell and the size of our social circle, Live Science reported.
In a 2020 study, people who were better at detecting the differences in everyday odors reported less loneliness.
Other studies have found that people with a more discerning sense of smell had more friends and a larger social network, as well as met with them more often.
The Unconscious Things the Nose Knows
Numerous studies have unveiled many things humans unconsciously note through their olfactory senses. Humans have a long history of consciously disregarding their noses. However, the brain and the smell receptors are logging this information unconsciously and reacting.
For example, one study noted that people tend to choose friends who are genetically similar to them and have similar body odor.
Mothers can identify their baby by its smell after spending as little as 10 minutes together. Newborns can recognize their mothers as well.
Tests on adult humans found they could match identical twins by their body odor.
Further, a 2022 study by researchers at the Weizmann Institute of Science compared the body odor of volunteers and was able to predict which volunteers would bond together. The research used both human smellers and an electronic nose. These findings also complement other studies that found humans subconsciously choose friends who share some of the same genes.
Another study found that people who shook hands with others of the same gender reflexively sniffed their right hand more than twice as often as they did before the greeting.
