You might observe a lot of facial hair trends around, and naturally assume it’s all about attracting a partner. However, the story behind why males grow facial hair may be more complex than simple attraction.
What is the evolutionary purpose of a beard? Children, women, and many men manage perfectly well without them. Yet, beards, in various styles from neat stubble to elaborate mustaches and full hipster beards, are a prominent feature of male appearance today.
It’s easy to jump to the conclusion that men groom and style their beards to attract women. But research into beards and voices suggests a different primary driver: beards likely evolved, at least in part, to enhance a man’s status and standing amongst other men.
Compared to many other primates, human males and females exhibit significant physical differences, a phenomenon known as sexual dimorphism. Facial hair in men is a key contributor to this difference. Often, these distinctions are attributed to sexual selection, the evolutionary process favoring traits that increase mating opportunities.
While sexual selection plays a role, the idea that beards primarily evolved to attract women is not strongly supported. Interestingly, women’s preferences regarding beards are quite varied. Some studies indicate women prefer men with some facial hair or even a lot, while others suggest a preference for a clean-shaven look. This inconsistent evidence makes it difficult to conclude that female attraction was the main evolutionary force behind beards.
This leads researchers to consider another form of sexual selection: male-male competition. Reproduction isn’t solely about attractiveness; it often involves competing with rivals for mating opportunities. In this competitive landscape, traits that confer dominance can be advantageous. Evidence suggests that beards evolved to help men gain an edge in these male-male contests.
A man’s capacity to grow a full beard isn’t directly linked to testosterone levels. Despite this, studies consistently show that both men and women perceive bearded men as older, stronger, and more aggressive. Dominance can significantly increase mating opportunities by allowing dominant individuals to outcompete rivals.
This principle applies both in contemporary society and throughout history. Dominance provides a considerable advantage in securing mates. For example, genetic evidence indicates that approximately 8% of the male population in Asia today are descendants of Genghis Khan, a historically dominant figure.
Research by Nigel Barber, linking beard fashion trends in Britain between 1842 and 1971 to the ratio of men to women in the marriage market, supports this idea. The study revealed that beards and mustaches became more fashionable during periods when there was a higher proportion of single men competing for a smaller pool of women. This suggests facial hair served as a competitive advantage in times of heightened male rivalry.
Beards are not the only trait that can signal dominance; voice pitch also plays a role. People tend to favor leaders with lower-pitched voices, and men often lower their voice pitch when they perceive themselves as more dominant than their opponent in competitive situations. Similar to facial hair, voice pitch is a noticeable difference between men and women.
To investigate the evolutionary origins of beards and voice pitch, researchers explored whether these traits were perceived as attractive, dominant, or both. In a study, men and women rated the dominance and attractiveness of men filmed at different stages of beard growth. Additionally, the men’s voices in the videos were digitally manipulated to sound higher and lower pitched.
The findings indicated that deeper-than-average male voices were rated as most attractive. Extremely deep or high-pitched voices were less favored. Conversely, the perception of dominance increased as voice pitch decreased. While beards didn’t consistently affect attractiveness ratings, men with beards were consistently perceived as more dominant, aligning with previous findings.
This tension between attracting mates and competing with rivals extends beyond beards and voices. Men, on average, desire a more muscular physique than women report finding attractive, while women often believe they need to be thinner and wear more makeup than men actually prefer. Our perceptions of attractiveness are complex and influenced not only by mate preference but also by the need to outcompete our peers.
It’s important to note that much of this research has been conducted in Western populations. Factors like makeup use, body composition ideals, and even the ability to grow facial hair vary significantly across the globe. This suggests that research in diverse populations might yield different results.
However, the overarching principle remains: whether it’s facial hair or other traits, the interplay of mate attraction and same-sex competition shapes the evolution of our appearances. The idea of universally pleasing everyone is unrealistic, as evolutionary pressures often pull us in different directions.
This article was adapted from content originally published on The Conversation under a Creative Commons license.
