Can people smell fear? A new study says that it is possible to smell fear but it seems that only women have this superpower. Scientists took samples of sweat from anxious people during a public speaking event and compared them to the samples of sweat from relaxed people playing sports.
According to Daily Mail, the team investigated the effects of chemosensory anxiety signals on 214 men and women by having them smell the samples of sweat via a hospital oxygen mask and while playing five games. They found that it predominantly affected women's risk-averse behavior and made them less trusting.
People Can Communicate Via Chemosensory Anxiety Signals
A paper in Frontiers in Psychology explained that the experience of stress can be communicated between people via chemosensory anxiety signals that are activated by the sympathetic-adrenal medullary (SAM) system that operates closely with the hypothalamus-pituitary-adrenal (HPA) axis.
People would sweat in response to that, fear, anxiety, and the release of alarm signals. Sweat is one of the physiological markers that a person is anxious or feels fear in specific situations.
According to PsyPost, recent findings provided evidence that like animals that use their sense of smell to detect predators and threats in their environment, humans can also detect stress or fear via chemosensory anxiety signals.
Researchers pointed out that the findings were surprising because people are able to communicate their motivational and emotional state via chemosignals even without doing consciously. Previous studies only showed the effects of chemosignals on the brain but not on the overt behavior of humans.
Anxiety Signals Might Be Used By Female Ancestors to Ensure Survival
As reported by Daily Mail, the findings of the study could explain the social evolution of women. In the study, titled "It's Trust or Risk? Chemosensory Anxiety Signals Affect Bargaining in Women" published in Biological Psychology, researchers from Heinrich Heine University in Dusseldorf a series of five studies to examine whether chemosensory anxiety signals reduced trust and risk behavior.
They compared the results to an experimentally verified computer task called The Trust Game to measure its trustworthiness. Both the game played and the computer produced similar results that chemosensory anxiety signals are more pronounced on women.
Anxiety signals released by the body during fearful or threatening situations prompted female ancestors to use their social networks. This was best displayed when a predator was lurking that presents harm to children. Mothers would need to ensure their safety and survival by bonding with others for joint protection.
This "friendly behavior" made some women more sensitive to subtle signals of fear and anxiety felt by others compared to men. Researchers said that when women detect chemosignals of fear and anxiety, they tend to play in a less trusting and more risk-averse way.
For example, they transferred less money to other participants in a financial investment game when they smelled chemosensory anxiety signals in the sweat compared to other odors. This was also observed even when the odor from the anxiety-induced sweat is not present.
Although men seem to be less reactive to chemosensory anxiety signals, that does not mean that they are unresponsive to these cues. Studies have shown that the smaller of the chemical from decaying dead bodies, called putrescine, induce threat management responses from both men and women.
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