Glossary
What is facial symmetry?
Last updated: May 22, 2026
Facial symmetry refers to bilateral correspondence between the left and right halves of the face. Higher bilateral symmetry is consistently rated as more attractive across cultures, age groups, and gender. Bilateral symmetry has been shown to account for approximately 62% of variance in attractiveness ratings when other factors are controlled (Little, Jones & DeBruine 2022).
How facial symmetry is measured
Measured by comparing corresponding landmark positions on the left and right sides of the face. Sub-millimeter differences register. Most faces are mildly asymmetric; perfect symmetry is rare and can actually read as uncanny.
Why facial symmetry matters
Symmetry correlates with health markers (immune function, pathogen load, hormonal balance during development) which is part of why it is perceived as attractive at the level of evolved preferences. Severely asymmetric faces (often the result of dental or skeletal issues) can be corrected through orthodontic and surgical interventions.
Normal range
Most faces are mildly asymmetric (sub-millimeter to a few millimeters of left-right difference). Moderate asymmetry (5+ mm differential) becomes visible. Significant asymmetry typically has an underlying cause (dental, skeletal, posture, sleep habits, prior injury).
Source: Little, Jones & DeBruine 2022 (Philosophical Transactions B)
How Facet uses facial symmetry
Facet measures bilateral symmetry across multiple landmark groups (brow, eye, nose, lip, jaw lines). Symmetry scores feed into individual module scoring and the overall harmony composite.
Frequently asked
Is anyone perfectly symmetric?+
No. All faces have some bilateral asymmetry. Perfectly symmetric faces are rare and can actually read as uncanny or 'too perfect' in photos.
Can I improve my facial symmetry?+
Some asymmetries are correctable. Orthodontic treatment, postural changes (avoiding chronic one-side sleeping or jaw clenching), and skin treatment can all reduce visible asymmetry. Surgical correction is available for significant skeletal asymmetry.
Why are some asymmetries normal?+
Mild asymmetry is normal and even contributes to a face looking 'human' rather than CGI. Most cosmetic interventions for asymmetry focus on the moderate to significant range, not on micro-asymmetries.