Facial Dimorphism and Beauty: An Evidence Based Guide

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.

Sexual dimorphism on display: the ornamented male mandarin duck (drake) exhibits exaggerated secondary sex traits for mate attraction

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.

Non‑human primates exhibit pronounced body size dimorphism, whereas humans show reduced size divergence. 

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. 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

Drag the slider to see how a male face changes when dimorphic characteristics are exaggerated

Before

After

Drag the slider to see how a female face changes when dimorphic characteristics are exaggerated

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.

• 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.

Individual features may be extremely similar in men and women. When we look at all features in conjunction, we can easily identify sex.

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.