COPY - Facial Dimorphism and Beauty: An Evidence Based Guide

Fundamentals of Beauty Series

TL;DR

Facial sexual dimorphism refers to the differences between masculine and feminine facial traits. Feminine features in women are linked to youthfulness and fertility and reliably raise attractiveness across cultures. Male facial masculinity is preferred by certain groups and in specific contexts, but there is no universal preference.

Roadmap to Sexual Dimorphism

In this series, we cover the fundamentals of facial aesthetics: averageness, symmetry, sexual dimorphism, neoteny, proportionality, and adiposity. In this article, we will discuss masculine and feminine facial traits, referred to as sexual dimorphism in the scientific literature. The roadmap below shows how this article links to the other core tenets at a glance.

Abstract

In facial aesthetics, sexual dimorphism refers to typical differences between men and women in their facial features. Sexual dimorphism plays a key role in attractiveness and is regarded as one of the six fundamentals of beauty. Across studies, cultures, and age groups, findings show that increased femininity consistently enhances female facial attractiveness, and it is thought to signal youthfulness and fertility. Conversely, there is no universal preference for masculine faces, but in short-term contexts and for certain groups of people, highly dimorphic male faces are preferred. Femininity is therefore essential for women’s aesthetics, while masculinity may be advantageous only in specific situations. Sexual dimorphism should be optimised while considering the other fundamentals of facial aesthetics, as harmony between features outweighs extreme traits.

QOVES Opinion

At QOVES, we see facial sexual dimorphism as vital to women’s aesthetics but secondary to men’s attractiveness. Enhancing feminine traits reliably increases perceived attractiveness in females, regardless of culture or population. Men with specific partner preferences or in particular contexts could benefit from increasing masculine traits, but for most, increasing masculinity will neither hurt nor improve their attractiveness.

What is Facial Sexual Dimorphism?

In simple terms, sexual dimorphism refers to the physical differences between males and females. In this sense, facial sexual dimorphism in humans refers to facial characteristics that are generally found in men and women. Facial dimorphism is a result of hormonal changes related to testosterone and oestrogen, which take place during puberty.

Biologists talk about two types of dimorphic characteristics: primary sex differences and secondary sex differences.

Primary characteristics

These are directly related to reproduction and mating. In other words, they refer to the different sexual organs found in males and females. Primary sex characteristics are not often discussed in the context of “sexual dimorphism”. Instead, this term is usually reserved to talk about secondary sex characteristics.

Secondary characteristics

These are all of the sex differences that are not directly related to reproduction. Think of height, body mass, or facial hair. They are highly variable in expression across species, sometimes reaching spectacular levels, for example, in plumage differences in mandarin ducks.

Body dimorphism

One of the most evident secondary sex differences is body mass dimorphism. In humans and most primates, males are larger than females. This is also highly variable; in gorillas and orangutans, for instance, males are sometimes more than twice as large as females. In humans, however, this difference is much smaller. Men are often 7-8% taller than women and weigh about 15% more, on average1.

Facial dimorphism

Sexual dimorphism is also evident in human faces. This, of course, is the focus of the present article. Facial sexual dimorphism can be defined as the degree to which male and female faces differ in shape and features.

Before

After

Features like jaw size and angle, brow prominence, and facial structure strongly diverge at puberty due to hormones (testosterone and oestrogen). Dimorphic traits shape our perceptions of masculinity and femininity, but what exactly makes a face look more masculine or feminine?

Before

After

What Makes a Face Feminine?

These facial features are more pronounced in females and therefore contribute to our perceptions of femininity. Some are more variable across populations, and some weigh more for our perceptions of femininity. In no particular order, these are dimorphic characteristics of female faces:

• Fuller lips: Increased lip vermillion height is strongly associated with femininity4–6.
• Larger, wider eyes: Greater eye height and width ratios contribute to a more feminine appearance2,5.
• Prominent cheeks and midface: A more pronounced middle third of the face with narrower but prominent cheekbones are key feminine markers2,5.
• Smaller, narrower jaw and chin: Less prominent mandibular angle and chin, with a softer jawline2-4.
• Higher, arched eyebrows: Eyebrows tend to be thinner and sit higher on the brow.
• Narrower nose: Shorter and narrower nose compared to masculine faces4–6.
• Brow and Forehead: Smoother, less pronounced brow ridge, which sits higher in the face. A more rounded forehead contour2,5.
• Smoother skin: A smoother, less rugged and often lighter skin4–6.
• Overall softer, less angular features: Feminine faces are generally characterized by smooth contours and less pronounced bone structure2, 5.

What Makes a Face Masculine?

The facial traits listed below are a result of testosterone during puberty and are associated with masculinity. In no particular order, these are dimorphic facial features of males:

• Broader, more angular jaw and chin: Increased jawbone prominence, a wider mandible, and a sharper mandibular angle are hallmarks of masculinity4–6.
• Pronounced brow ridge and thicker eyebrows: The brow is more prominent, and eyebrows are thicker and straighter. This gives the appearence of smaller eyes2, 5.
• Longer, wider face: Greater upper and lower facial third ratios, with increased facial height and width2,5.

What about teeth? Although there are consistent sex size differences in canine teeth in humans, no studies have examined their role in facial attractiveness. The research team at QOVES is currently conducting original research on this topic.

• Wider nose: Masculine faces often have a broader nose2,3.
• Thinner lips: Lips are typically less full than in feminine faces2,5.
• Lower, flatter cheeks: Cheekbones are less prominent compared to feminine faces4,5.
• M-shaped or receding hairline: Adds to perception of maturity, and more common in masculine facial profiles2-4.
• Facial Hair and Skin. Facial hair and rougher skin texture (studies on facial dimorphism almost always use clean-shaven faces to focus on structural features)2-4.
• Neck. Technically not part of the face, but a thicker and more muscular neck is perceived as more masculine7.
• Overall robust, more angular facial structure. A more ‘robust’ and defined bone structure, including wider cheekbones and a longer midface. In general, a broader, more square face shape2,5.

Why Single Features Mislead

An important point here is that perceptions of masculinity and femininity come from configurations, not single features. Most individual facial traits overlap between men and women: plenty of men have small noses, and plenty of women have strong jaws. For example, consider the set of lips on the faces below; it is hard to determine sex based on this trait alone and the same pair of lips can be present in both men and women without looking out of place. However, when seeing a whole face, the pattern of multiple dimorphic features allows humans to accurately identify the sex of a face8, 9.

What signals masculinity or femininity is the composite of many dimorphic traits at once that, when taken together, make sex classification highly reliable, even though any one feature is a weak indicator of sex on its own4,10–12.

How is Sexual Dimorphism Attractive?

More feminine (sexually dimorphic) faces are generally rated as more attractive across populations. This is observed in different research studies, using both manipulated and unedited, natural faces. Research shows that a composite of very attractive female faces has more feminine features than a composite of all women in a population13,14. If you ask people to describe or create a beautiful female face, they will typically include feminine traits like fuller lips and smaller chins. Overall, all of these results reach the same conclusion: femininity is desired and considered attractive in female faces12.

The appeal of masculine faces is a current topic of debate in the scientific community. The results are complex and far from conclusive. To some, more masculine traits are considered attractive, whereas many prefer more neutral or even slightly feminised traits in male faces15. The current evidence suggests there is no universal preference for facial masculinity like there is for facial femininity12. However, particular demographics do show more consistent preferences for more traits, a topic we discuss in detail in the section Who Likes Masculine Faces?

There are a number of theories as to why facial dimorphism plays a role in attractiveness and partner preferences. For many years, the leading hypothesis was that they are the result of sexual selection, with more masculine faces signalling health, high testosterone levels, and social status. Feminine faces are instead thought to reflect youthfulness, fertility, and reproductive fitness6. However, more recent work has suggested that preference for facial dimorphism (in males in particular) is largely influenced by cultural and ecological context, which challenges the idea of an innate biological predisposition. We explore both of these hypotheses in “Why is Dimorphism Attractive?”

The Benefits of Facial Dimorphism

Facial sexual dimorphism doesn’t just change beauty scores; it also shapes social impressions, romantic outcomes, and even workplace judgments. Of note, the benefits are sex-asymmetric: increasing femininity in women reliably boosts attractiveness and advantages across contexts, while masculinity in men brings context-dependent trade-offs, which we discuss below4,10–12

The Femininity Dividend

Across populations, more feminine female faces, those with fuller lips, a smaller chin, and a smoother brow, are consistently judged more attractive9,12,16. That increased attractiveness reliably brings about a broad range of social advantages.

Halo Effect (’What is Beautiful is Good’)

People naturally associate a single positive attribute (like attractiveness) with a large number of positive judgments in other domains. Research has shown that attractive, feminine faces tend to be perceived as more intelligent, sociable, emotionally stable, and trustworthy17,18. This is also known as the classic "What is Beautiful is Good" phenomenon and is considered to be a cognitive bias for beauty. These positive attributions generalise to real outcomes (hiring, pay, social inclusion), and the gains are often larger for women19–22.

Purity Bias

Humans have a tendency to infer moral worth from attractive faces. The field of moral psychology has found that attractive faces are taken to be more pure and less capable of moral wrongdoing23. Feminine female faces especially benefit from "cleanliness/purity" perceptions that reduce perceived likelihood of norm violations.

Health & Fertility Signal

Femininity in women is strongly tied to oestrogen-linked traits and neoteny, meaning that it acts as a signal of youth, fertility, and overall reproductive health. The result is that feminine traits are preferred cross-culturally ("fertility hypothesis"). Even if objective health links vary, the perception of health/fertility is robust, and perceptions strongly drive choice10,24.

Dating Dividend

Increasing femininity reliably improves mate desirability and expands options in both short- and long-term contexts, with supportive evidence across manipulated and natural faces14.

The Confidence Loop

Improved appearance, through increased feminine facial features, can positively impact self-perception. Studies reveal that people with a more positive self-image carry themselves in more attractive ways, with an improved posture, a steadier gaze, and increased social approach25,26. It is considered a loop because increased confidence leads to attractive behaviours, which in turn lead to positive social feedback, increasing confidence again.

Self-Esteem Multiplier

Achieving a glow-up or enhancing facial aesthetics can elevate one’s self-esteem, which in itself is associated with a large number of positive benefits27. Psychological research has shown that self-esteem is associated with better mental health, resilience, improved interpersonal relationships, and life satisfaction26,28.

The Masculinity Trade-Off

By contrast, facial masculinity in men (pronounced brow ridge, wider jaw, longer lower face) brings mixed returns. Preferences for highly masculine male faces are not universal and often vary with ecology and culture; some populations prefer neutral or slightly feminised male faces11,29. Masculinity can signal dominance and physical strength, but it can also reduce perceived warmth, honesty, and parental investment, which matters for long-term partner choice10. In this scenario, enhancing masculine features can give you an advantage in certain fields, but often at a cost.

Dominance & Strength Signal

More masculine faces are read as physically stronger and higher-status30, which can confer advantages in zero-sum or competitive contexts (male-male competition, protection/status heuristics). This is the clearest upside of male facial masculinity.

Short-Term Mating Advantage

Some studies have suggested that masculine faces can attract short-term interest in some contexts31; however, the same traits may not convert to long-term choice when care, warmth, and reliability are prioritised. Increasing masculine facial features, nevertheless, might give you the upper hand in short-term mating scenarios.

Warmth & Trust Trade-Off

The cost side: highly masculine male faces are often judged as less cooperative and lower in parental investment (an echo of the “dominance vs. dad” trade-off)15. An overall attribution of poor prosocial attributes to very masculine faces can hurt long-term partnership prospects or leadership evaluations in high-trust, collaborative environments10,15.

Health and Immunocompetence

The classic immunocompetence handicap account predicts that masculine traits signal robust genes despite testosterone’s costs, but empirical support is weak and inconsistent, and preferences don’t increase under high pathogen load as the theory would predict32,33. In practice, the evidence is inconclusive34, but there is a chance that masculinity could signal robust health.

Workplace Perception

Context is crucial, masculine faces may benefit in competitive, risk-prone roles in which assertiveness, dominance, and aggression are valued, yet backfire in roles demanding approachability, trust, and empathy.

In summary: The effects of facial sexual dimorphism are sex-asymmetric. Feminine cues in women tend to stack the Halo, Purity, Competence, Dating, and Confidence effects. Masculine cues in men deliver dominance and strength signals with important trade-offs for trust and long-term partner value. For men, understanding and carefully considering the perceptions associated with masculine traits is key to turning facial dimorphism into advantage.

Why is Dimorphism Attractive?

Evolutionary Theory

This perspective states that beauty standards have been shaped by mate choice pressures in our evolutionary past. Leading American anthropologist Donald Symons (1979) argues that standards of human beauty are not arbitrary cultural inventions, instead, they reflect psychological adaptations shaped by sexual selection to detect reproductive value and mate quality. In simple speak, humans have been wired to like what increases their chances of successful reproduction.

The Fertility Hypothesis

In this view, facial femininity in women signals youth, fertility, and overall reproductive fitness. In turn, men would find this more attractive and males that selected more feminine females would ‘outreproduce’ those that did not. In a study published in the prestigious journal Nature10, Perrett and colleagues state that oestrogen-dependent characteristics of the female body correlate with health and reproductive fitness and are thus found attractive. In 2000, Johnston formally laid out the Fertility Hypothesis and explained that oestrogen during puberty slows lower-face bony growth and promotes feminine and neotenous proportions, such as fuller lips, and a smaller jaw and chin24. Given that facial dimorphism becomes more apparent after puberty, it is taken to be a sign of sexual maturity and reproductive fitness3. Research has demonstrated a universal liking for feminine facial traits, consistent with the Fertility Hypothesis.

Immunocompetence Handicap Hypothesis

This hypothesis states that masculine facial traits reflect genetic quality and are therefore favoured. Originally proposed by Folstad and Karter (1992), the core idea is that testosterone boosts the development of masculine features and, at the same time, suppresses immune function, meaning that only those with superior immunity could withstand the costs of high testosterone. This theory would predict that preference for more masculine traits would be stronger in high-pathogen contexts, as selecting for health would be more crucial. However, evidence shows the opposite: facial masculinity is actually preferred in urban, industrialised settings11,29. Overall, empirical support for this theory is rather weak.

The Dominance Theory

Another theory regarding masculine faces states that it is not about reproductive health, but rather about what it communicates about status and social behaviour35,36. Whereas men are tuned to detect fertility and reproductive fitness, women instead are sensitive to signals of status, resource acquisition capacity, and parental investment willingness. A masculine face may be perceived as more dominant and a higher social rank, which could have historically appealed to women, as dominant males have greater access to resources and may provide better protection3,36. Research shows that men with more masculine faces tend to have more muscular bodies and physical strength7, which would’ve been advantageous for male-male competition in the past.

Parental Investment and Social Perception

As humans evolved, social structures changed toward more monogamous, cooperative societies, away from intense male-male competition and aggressiveness. Very masculine features may actually signal undesirable traits for long-term partners, like aggressiveness, unfaithfulness, or dishonesty15. Women may then choose to avoid extremely masculine faces, opting instead for a more moderate combination of social status, health, and parental investment. This is consistent with modern research, which reliably shows that very masculine faces are indeed associated with dominance but also with less warmth, honesty, cooperativeness, and quality as a parent37,38.

One example of this is the fact that our primate ancestors showed extreme levels of sexual dimorphism in the canines (very large on males); humans instead show minimal differences, potentially a result of female selection against extremely masculine traits.

Cultural Influences

The role of cultural influences on the perception of sexual dimorphism has been starting to gain attention in response to mixed and conflicting results on the relationship between facial masculinity and attractiveness. Whereas a preference for feminine traits occurs all over the world, and seems to be a result of innate biology, the role of masculine features is poorly understood.

Learned Stereotype and Status Signal

A highly cited study by Scott and co-authors found that people in small-scale societies (hunter-gatherer or farmers) did not show a preference for high sexual dimorphism, compared to those in urban and industrial populations11. The authors theorise that this might be a result of a “learned stereotype” in which very masculine men are often portrayed in the media as dominant and higher-ranking in the social structure. Another view is that, as societies develop, people can gain highly differentiated status from roles that don’t exist in other places. It is plausible that more masculine-looking faces are associated with those roles, either due to a real relationship or due to media portrayals, which would shift what people find attractive. However, some of the latest studies have found no relationship at all between masculinity and attractiveness16.

Facial masculinity, therefore, appears to respond to surrounding social and cultural conditions to a greater extent than symmetry, averageness, and facial femininity, which show universal effects.