Scientists map the visual patterns people use when evaluating others’ bodies

A new study has mapped the visual patterns people use when judging bodies, finding that attention is most concentrated on the chest and torso. Researchers used eye-tracking to show that these gaze patterns are influenced by a body’s mass index and the specific judgment being made. The findings were published in Behavioral Sciences.

While previous research has shown that people form quick and consistent impressions based on physical appearance, including body shape and size, relatively little is known about where people look during these evaluations. Most earlier studies focused on attractiveness alone, often using photos or single-sex models. The team behind the new study aimed to explore how body mass index influences not only people’s ratings of attractiveness, health, and youth, but also their gaze patterns as they make these judgments.

“The work was done with my undergraduate student and co-author, Marianne Lanigan. She was interested in using eye-tracking for her university research project, and so we combined this with my interest in social perception – judgements we make about other people,” said study author Edward Morrison, a senior lecturer at the University of Portsmouth.

“There is lots of research about how we judge other people from the way they look, including how fat or thin they are, but there is less on how people’s eye movements differ when looking at these bodies, and nothing about eye movement when making different judgements on the same bodies. In our case, we looked at judgements of attractiveness, healthiness, and youthfulness, all of which are suggested to be evolutionary indicators of fitness.”

To investigate this, the researchers recruited 32 participants, mostly university psychology students, with a mean age of about 20 years. Most were female and identified as heterosexual or bisexual. The study was conducted in a controlled laboratory setting, where participants viewed digital images of male and female models that varied systematically by body mass index. The computer-generated models, created using an online tool, were standardized in height but differed in body weight to simulate underweight, low healthy weight, high healthy weight, overweight, and obese categories.

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Participants were asked to rate each model on three dimensions—attractiveness, healthiness, and youthfulness—using a six-point Likert scale. While doing so, an eye-tracking device recorded where and for how long they looked at different parts of the body, including the head, chest, midriff, thighs, and lower legs. Each image was displayed for five seconds, and participants completed a series of trials, first rating all five female models for attractiveness, then for health and youth, and repeating the same process for the male models. The image presentation order was counterbalanced to reduce bias.

The researchers analyzed both the eye-tracking data and the rating scores. They found that visual attention was not distributed evenly across the body. The chest and midriff received the most fixations and the longest viewing times, while the thighs and lower legs received the least. Interestingly, participants tended to look longer and more frequently at male models than at female ones. This pattern may have been influenced by the predominance of heterosexual women in the participant pool.

The part of the body that received the most attention shifted with the model’s body size. At lower body mass indexes, people spent more time looking at the midriff, while at higher weights, their gaze shifted more toward the chest. Attention to the head increased as the body mass index increased, possibly reflecting associations between weight and age. These changes occurred even though participants were not consciously asked to evaluate specific body regions.

Different types of social judgments also subtly influenced gaze behavior. When participants judged youthfulness, they tended to look more at the head, compared to when they judged attractiveness or healthiness. This makes sense given that the face carries many visual cues related to age. Ratings for healthiness led to more focus on the chest and midsection, areas associated with visible fat distribution and muscularity.

When it came to the actual ratings, participants judged the lower end of the healthy weight range as most attractive and most healthy. Youthfulness ratings, in contrast, peaked for the lightest bodies—those classified as underweight. This may reflect cultural and evolutionary associations between slimness, youth, and reproductive potential. As body mass index increased, youthfulness ratings declined steadily for both male and female models.

There were also some differences in how participants evaluated male versus female bodies. Underweight male models were rated significantly lower in attractiveness and healthiness than underweight female models. This may reflect how low musculature, which often comes with lower body weight, is viewed negatively in men. For female models, even those just under the healthy weight threshold were still rated highly for attractiveness and youth. This aligns with cultural ideals that tend to favor leanness in women more than in men.

The researchers also found interactions between the sex of the model, the rating type, and body mass index. For instance, the healthiest-looking male model had a slightly higher body mass index than the most attractive one, suggesting that participants may associate some muscularity with health. This contrasts with previous studies that found people often prefer slimmer bodies even if they appear less healthy. The discrepancy could be due to cultural differences, as earlier studies showing that pattern used samples from Asian populations, whereas the current study primarily involved participants of European descent.

“We seem to look at different parts of the body when viewing bodies of different size,” Morrison told PsyPost. “We also look at different parts of the body when making different judgements. The differences are subtle but detectable when analyzing the eye-tracking data. It is not straightforward to explain the pattern of differences, but overall they suggest that we look for subtly different physical cues when judging attractiveness vs. healthiness vs. youthfulness.”

While the study provides new insight into the way people use visual cues to judge others, it has some limitations. The sample size was small and heavily skewed toward young women, which may limit how well the findings apply to broader populations.

“Results may be different if we had enough male viewers to compare, as other studies suggest,” Morrison noted. “Our stimuli were also computer-generated models without faces or clothing (but no genitals). This was so we could experimentally control body size while keeping everything else constant. However, we may look at computer-generated models differently from real people.”

The researchers suggest that future studies should include a more balanced mix of participants in terms of sex and age. They also propose exploring how people’s own body image and experience might shape their judgments of others. Studies in more naturalistic settings, such as using wearable eye-trackers while observing people in public, could also help confirm whether the patterns observed in the lab reflect real-world behavior.

The study, “Shape of You: Eye-Tracking and Social Perceptions of the Human Body,” was authored by Edward Morrison and Marianne Lanigan.