How Long and How We Judge Age: A Cross-Racial and Cross-Gender Eye-Tracking Investigation

Facial aging results from genetic, environmental, and lifestyle factors, leading to wrinkles, volume loss, and contour changes. These alterations affect perceived age, attractiveness, and self-image. Eye-tracking technology provides insights into gaze patterns, revealing how specific facial regions influence age-related judgments.

This study aimed to examine the role of different facial regions in rapid age estimation, with a specific focus on the midface. We investigated decision times, gaze patterns, and their implications for aesthetic interventions, particularly for middle-aged individuals.

Fifty-four participants evaluated 60 digitally generated facial images representing diverse ethnicities, genders, and three age groups (young, middle-aged, and older). Eye movements were recorded using a Tobii Pro Nano eye tracker. The custom-defined Times of Interest (TOIs) were defined as the decision times for categorizing images as "young" or "old". Fixation durations were analyzed for predefined Areas of Interest (AOIs), including the upper face, midface, and lower face, further subdivided into left and right sides. Non-parametric statistical tests were used to identify differences between groups.

Decision times were significantly longer for middle-aged stimuli (1489.49 ± 1055.56 ms; p < 0.001) compared to young (1021.98 ± 480.24 ms) and older stimuli (1048.31 ± 726.03 ms). Stable fixation duration was longest for the midface (863.50 ± 564.48 ms; p < 0.001), followed by the lower face (105.99 ± 238.70 ms) and upper face (25.34 ± 116.42 ms). Middle-aged stimuli consistently elicited the longest fixation times across all regions (p < 0.001). No significant differences were observed between male and female stimuli for midface fixation (p = 0.393). However, male stimuli attracted longer fixations in the upper face (p = 0.001), while female stimuli drew attention to the lower face (p = 0.039). Right-sided facial regions consistently received longer fixation durations across all stimuli characteristics (p < 0.001). Asian participants showed shorter fixation times in the midface but longer fixations on the lower face compared to Caucasian participants (p < 0.001).

The midface emerged as the focal region for age perception, with its structural prominence and association with age-related changes driving prolonged visual attention. Longer decision times for middle-aged faces reflect their complexity, requiring detailed processing of both youthful and aging features. These findings underscore the importance of prioritizing the midface in aesthetic interventions, particularly for middle-aged patients. Understanding gaze patterns can guide aesthetic providers in developing personalized, effective rejuvenation strategies that align with natural age perception mechanisms.

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