Objective measurements shed light on the geometry of facial attractiveness

New research provides evidence that objective, measurable aspects of a person’s three-dimensional facial shape dictate how attractive they are perceived to be by others, with distinct geometric patterns emerging for men and women. The findings suggest that the specific facial features society deems appealing align closely with the physical traits that make individuals feel more attractive to themselves. The study was published in the journal Progress in Orthodontics.

Facial appearance serves as the primary visual tool humans use to gather information during initial social interactions. Within a fraction of a second, people unconsciously evaluate a stranger’s face to form lasting impressions about their trustworthiness, competence, and overall health. These rapid judgments do not require complex cognitive thinking and happen almost automatically upon visual contact. Individuals who are perceived as physically attractive often experience favorable treatment in everyday life, which tends to lead to greater professional success and easier access to romantic relationships.

“Physical attractiveness influences many aspects of our daily lives and plays a critical role in everyday human interactions,” said study author Georgios Kanavakis, an assistant professor in the Department of Orthodontics at the School of Dentistry at the National and Kapodistrian University of Athens. “From first impressions and simple acquaintances, to professional opportunities and romantic relationships. While we often think of beauty as being entirely subjective, decades of research have shown that people tend to agree surprisingly well on which faces they find attractive.”

Understanding the exact physical geometry that makes a face attractive has fascinated scientists across multiple disciplines. “The primary motivation for patients to seek orthodontic treatment is to improve their facial and smile appearance and therefore orthodontists have always focused on these topics,” Kanavakis explained. “My colleagues and I have always been interested in understanding which aspects of facial morphology contribute to the perceptions that facial appearance creates.”

The research team previously conducted two related studies to understand how people view their own faces. In one prior study, they found that specific objective facial shapes heavily influenced how attractive participants felt they were. In that sample, women who rated themselves as highly attractive tended to have narrower faces and fuller lower features. Men who felt highly attractive possessed prominent chins, flatter cheeks, and pronounced eyebrow ridges.

In another previous study, the same research group demonstrated that a woman’s objective facial shape is statistically linked to her internal feelings of self-esteem. Women with fuller, more projected lips reported higher self-esteem, hinting that individuals might internalize external beauty standards to judge their own self-worth. Building on these previous findings, the scientists designed the current study to see if external evaluators share the exact same visual preferences as the individuals rating their own faces.

“Our previous work showed that certain facial characteristics are associated with how attractive people perceive themselves to be,” Kanavakis said. “The natural next question was whether those same facial features also influence how attractive others perceive them. This study allowed us to directly compare self-perception and external perception in the same individuals using highly detailed three-dimensional facial imaging.”

To thoroughly investigate this concept, the researchers recruited a sample of 601 young adults between the ages of 21 and 35. This group consisted of 393 females and 208 males from various ethnic backgrounds, all of whom identified as heterosexual. The participants were primarily medical and dental students who were raised in the United States and spoke English as their native language.

The research team utilized a specialized three-dimensional camera system to capture a highly detailed surface image of each participant. The participants were instructed to maintain a resting, neutral facial expression with their teeth lightly touching and their eyes open. This standardized posture ensured that temporary muscle expressions, like smiling or frowning, did not alter the natural baseline structure of the face.

To translate these physical faces into measurable data, the scientists applied a technique known as geometric morphometrics. This process involves placing 1,021 specific digital reference points, known as landmarks and semi-landmarks, across the computerized surface of each face. These digital markers map the unique curves, contours, and proportions of the underlying bone and soft tissue structure.

“One aspect of this study that I find particularly exciting is the use of three-dimensional facial imaging and geometric morphometric analysis,” Kanavakis noted. “Rather than relying on a few simple facial measurements or two-dimensional photographs, these techniques allow us to study the face as a complex three-dimensional structure. This provides a much more realistic picture of how facial shape relates to attractiveness and helps move research in this field beyond subjective impressions toward objective, quantitative analysis.”

Once the digital models were prepared, a panel of six external evaluators was brought in to rate the images. This panel included three men and three women who were the same age as the study participants, ensuring that generational differences in beauty standards did not skew the data. The evaluators viewed the three-dimensional images on a computer screen and could view the digital faces from multiple angles.

The evaluators independently rated the attractiveness of each face using a visual analogue scale. A visual analogue scale is a continuous measuring tool, often presented as a straight horizontal line on a screen. The raters mark a point on the line that represents their judgment, ranging from zero at the lowest end to 100 at the highest end. The scientists averaged the scores from the six judges to create a single external attractiveness score for each participant.

Because male and female faces develop differently due to hormonal influences, the researchers analyzed the two groups separately. “While attractiveness certainly contains a subjective component, our findings suggest that some aspects of facial shape are perceived consistently as attractive across observers,” Kanavakis told PsyPost. “So there are actually measurable shape differences between faces that are viewed as more attractive by external observers.”

For the female participants, the analysis revealed a statistically significant link between geometric facial shape and external attractiveness ratings. The researchers found that female faces rated as more attractive tended to feature a slightly narrower overall width. These highly rated faces also displayed reduced fullness in the cheek area, resulting in a more angular appearance with sharper, well-defined jaw contours.

Additionally, specific central facial features stood out in the attractive female group. The most attractive faces featured a slightly more prominent central facial area, specifically around the nose, and a somewhat longer lower face. Most noticeably, a fuller and more forward-projecting upper lip was highly characteristic of the female faces that received the top scores from the external judges.

In the male group, the statistical effect size was highly comparable to that of the females, but the mathematical numbers did not cross the strict threshold of absolute significance. “Another interesting observation was that the statistical association between facial shape and attractiveness was stronger in women than in men, even though the overall patterns were remarkably similar,” Kanavakis said. “We believe this may partly be due to the smaller male sample size and greater variability in male facial morphology, but it definitely also raises interesting questions about whether facial attractiveness in men depends relatively more on characteristics beyond facial shape alone.”

Despite lacking statistical significance, consistent visual patterns emerged for the highly rated male faces. Male faces deemed attractive by the judges tended to show a well-defined, angular structure with decreased roundness on the sides of the face. They exhibited a straighter facial profile and more prominent central features, particularly a stronger chin and a more pronounced lower forehead area.

The scientists also conducted a focused sub-analysis on the White participants, as they made up the largest relatively homogeneous ethnic subgroup in the study. In White females, the external raters once again preferred reduced cheek volume, an angular jaw, and increased forward projection of the upper lip. In White males, no meaningful statistical association was found between facial shape and external ratings, mirroring the statistical trends seen in the broader male group.

These external ratings align remarkably well with the group’s previous findings on self-perceived attractiveness. “Perhaps the most interesting finding was the strong similarity between self-perceived and externally perceived attractiveness,” Kanavakis said. “We expected some overlap, but the consistency was greater than anticipated, suggesting that people may internalize many of the same facial characteristics that society generally associates with attractiveness or that there is a universal, subconscious agreement regarding the features of an attractive face.”

The exact geometric traits that the external panel found attractive are the identical geometric traits that led participants in the earlier study to rate themselves as highly attractive. “Interestingly, we also found considerable agreement between the facial traits associated with how attractive people see themselves and how attractive they are perceived by others,” Kanavakis added. This strong alignment provides evidence that people judge their own physical appearance using the exact same geometric criteria that society uses to evaluate them.

“At the same time, facial shape explains only part of what makes a face attractive,” Kanavakis explained. “One important message is that facial attractiveness is influenced by measurable aspects of facial shape, but it is far from being determined by a single feature. Attractive faces were characterized by a combination of subtle traits that work together rather than by one ‘perfect’ nose, chin, or jawline.”

Certain limitations should be kept in mind when interpreting these study results. “Our participants were young adults, and the evaluators were also young adults with a health sciences background,” Kanavakis noted. “Although previous research suggests there is substantial agreement across different populations regarding many aspects of facial attractiveness, our findings should not be assumed to apply equally across all ages and cultures.”

Age is known to strongly influence attractiveness preferences, meaning that evaluators from an older generation might prioritize entirely different facial proportions. “In addition, we focused specifically on static three-dimensional facial shape,” Kanavakis said. “We did not evaluate dynamic facial expressions, skin quality, eye appearance or hairstyle, all of which can strongly influence attractiveness in everyday life.”

Future research should aim to replicate these geometric procedures in more diverse populations around the world to see if these physical preferences hold true across cultures. “Our long-term goal is to better understand how objective facial morphology interacts with psychological and social factors to shape perceptions of attractiveness,” Kanavakis explained. “We are particularly interested in investigating how facial shape relates to self-esteem, body image, and psychosocial well-being.”

“From a clinical perspective, we hope this work will help orthodontists and other clinicians develop more evidence-based approaches to facial aesthetic treatment planning,” he concluded. “Ultimately, the goal is not to create a single definition of beauty, but to better understand the biological and psychological factors that influence how people perceive themselves and others.”

The study, “Influence of facial shape on perceived attractiveness,” was authored by Nikolaos Gkantidis, Sven Stucki, Mohammed Ghamri, Demetrios Halazonetis, and Georgios Kanavakis.