No evidence was found to support the hypothesis that beards are honest (or dishonest) signals of the beard owners’ testosterone levels and dominance

Are Beards Honest Signals of Male Dominance and Testosterone? Marta Kowal, Piotr Sorokowski, Agnieszka Żelaźniewicz, Judyta Nowak, Sylwester Orzechowski, Grzegorz Żurek, Alina Żurek & Magdalena Nawrat. Archives of Sexual Behavior, Oct 21 2021. https://link.springer.com/article/10.1007/s10508-021-02012-w

Abstract: The male beard is one of the most visually salient and sexually dimorphic traits and a hypothesized potential marker of other traits, such as dominance, masculinity, social status, and self-confidence. However, as men can easily alter their facial hair, beards may provide unreliable information about the beard owner’s characteristics. Here, we examined whether beards are honest signals of biological (testosterone levels) and psychological (self-reported dominance) traits. Young (M = 21.29, SD = 1.54) and healthy men (N = 97) participated in the study. Their beards were measured directly (using digital calipers) and by self-report. Participants provided saliva samples before and after acute exercise (to assess their testosterone and cortisol levels) and reported their dominance on a 5-item scale. The results showed that beard length (directly measured and self-reported) was not related to testosterone levels or dominance; thus, no evidence was found to support the hypothesis that beards are honest (or dishonest) signals of the beard owners’ testosterone levels and dominance.