Can you smell the condition? Testosterone in body odor predicts perceptions of power

Superiority via smell: Study shows how perceptions of dominance are affected by a whiff of BO

Men with higher levels of testosterone produce body odors that others consider more dominant, according to research revealing how humans can communicate social status through smell.

The study published in Evolution and human behaviorExamined whether circulating testosterone affects how people perceive social rank through smell alone. Researchers at the University of British Columbia collected worn-out T-shirts from 74 male volunteers as well as saliva samples to measure testosterone levels. Then 797 people smelled the shirts and rated the wearer’s characteristics, including how dominant they were.

The men whose testosterone was measured had higher odors, which raters perceived as coming from more dominant individuals. This relationship persisted even after the researchers controlled for factors such as odor intensity, pleasantness, the ethnic background of the shirt wearers, and whether raters were male or female.

The study authors note that awareness of the social status of others is vital for individuals of social species. The ability to quickly assess whether someone poses a threat or could be a valuable ally would have provided evolutionary advantages throughout human history.

How does testosterone change body odor?

Testosterone plays many biological roles that can alter body odor. The hormone affects the function of the apocrine sweat gland, affects the production of sebum in the skin, and affects the growth of body hair. Each represents a potential pathway by which testosterone levels may alter the chemical composition or intensity of natural odor.

The study found that men with higher testosterone produced more intense body odors overall. But the relationship between testosterone and perceived dominance extended beyond odor intensity alone. Even when the researchers accounted for odor strength in the statistical models, testosterone still predicted dominance ratings.

The effect of testosterone appears to be specific to dominance rather than social status more broadly. The hormone showed no relationship to how prestigious evaluators thought T-shirt wearers were. This distinction is important because humans achieve high social status through two different strategies: dominance, which relies on force and intimidation, and prestige, which comes from demonstrating valuable skills that make others willing to follow them voluntarily.

Chemical signaling across species

Chemical signals represent the most widespread form of communication between organisms on Earth. Many vertebrates use scent to advertise competitiveness and social rank. Dominant male rodents mark their territories, and other males usually avoid these marked territories to avoid costly conflicts. Ring-tailed lemurs and some lizard species can detect testosterone-related scent cues from other members of their species.

Perhaps humans are exploiting this same ancient system. Previous research has shown that the smells of loved ones can trigger specific responses, that people can detect chemical signals of fear and illness, and that they evaluate the attractiveness of potential partners based in part on body odor. Several studies have reported that women can perceive dominance and other personality traits through a man’s body odor, although to date no one has directly tested whether testosterone levels drive these perceptions.

The current research included both male and female participants as odor raters and found no difference between genders. Both men and women have been shown to be able to detect dominance signals in body odor.

Unanswered questions about smell and condition

The research has not been able to determine whether scent-based impressions of dominance are actually accurate. While the researchers collected self-reported dominance ratings from the men who were provided the shirts, these self-ratings showed no relationship to testosterone levels or to how others perceived their scent. Social dominance relates to how others view and classify someone within the group rather than self-perception, so this disconnect does not necessarily mean that the scent cues were wrong.

The researchers measured testosterone at just one time point, providing a snapshot rather than a comprehensive picture of baseline hormone levels. Measuring average testosterone across multiple occasions is likely to yield more accurate estimates and potentially stronger relationships.

The shirts underwent 10 to 20 freeze-thaw cycles, with different groups of residents smelling them during multiple laboratory sessions, although this was not precisely tracked. Repeated thawing can allow bacterial activity that may alter odor quality. If freeze-thaw cycles reduce odor intensity, the results may actually understate the true relationship between testosterone and perceived dominance.

Why dominance but not prestige?

The fact that testosterone predicted perceived dominance but not prestige may reflect different evolutionary timetables for these two paths to social status. Dominance through force represents an ancient evolutionary mechanism that humans share with many other species. Prestige appears to be unique to humans and likely emerged recently as a result of pressures to recognize and learn from skilled group members.

If detecting dominance through scent provided survival advantages deeper into evolutionary history, natural selection would have had more time to improve this ability than detecting prestige. The biological systems that associate testosterone with body odor and the cognitive systems that allow others to interpret these signals may have been formed over millions of years of evolution.

The findings open new questions about how humans navigate social hierarchies through sensory channels they rarely recognize. From first impressions to workplace dynamics, the subtle chemical signals that people emit and detect may influence outcomes in ways worth better understanding.

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