Body Odor Quality Predicts Behavioral Attractiveness in Humans

Growing effort is being made to understand how different attractive physical traits co-vary within individuals, partly because
this might indicate an underlying index of genetic quality. In humans, attention has focused on potential markers of quality
such as facial attractiveness, axillary odor quality, the second-to-fourth digit (2D:4D) ratio and body mass index (BMI).
Here we extend this approach to include visually-assessed kinesic cues (nonverbal behavior linked to movement) which are statistically
independent of structural physical traits. The utility of such kinesic cues in mate assessment is controversial, particularly
during everyday conversational contexts, as they could be unreliable and susceptible to deception. However, we show here that
the attractiveness of nonverbal behavior, in 20 male participants, is predicted by perceived quality of their axillary body
odor. This finding indicates covariation between two desirable traits in different sensory modalities. Depending on two different
rating contexts (either a simple attractiveness rating or a rating for long-term partners by 10 female raters not using hormonal
contraception), we also found significant relationships between perceived attractiveness of nonverbal behavior and BMI, and
between axillary odor ratings and 2D:4D ratio. Axillary odor pleasantness was the single attribute that consistently predicted
attractiveness of nonverbal behavior. Our results demonstrate that nonverbal kinesic cues could reliably reveal mate quality,
at least in males, and could corroborate and contribute to mate assessment based on other physical traits.