Obscurity of eyebrows influences recognition of human emotion and impacts older adolescents

Facial features (e.g. eyebrows, mouth) give important visual cues to help convey emotions such as happiness, anger, and sadness. It is ultimately through these face-to-face interactions where accurate interpretation and response to facial expression benefits social-emotional development by helping humans foster strong interpersonal relationships. The problem is that recent societal factors, such as increased smartphone/social media use and the Coronavirus pandemic have reduced the opportunities to engage in natural, face-to-face social interaction. The purpose of our study was to determine whether the presence of eyebrows in photographs is essential for interpreting emotion and whether participant accuracy and/or reaction time (RT) is age-dependent. We hypothesized that eyebrow presence in unaltered control photographs would enhance participant recognition of emotion compared to experimental photographs with removed eyebrows and that participant accuracy and RT would differ by age group, especially between adults (21+ years) and adolescents (12-18 years). Our findings revealed that removing eyebrows results in a significant decrease in participant accuracy to recognize anger from experimental facial images. In addition, upper school (US) adolescents (15‑18 years) were more likely to misidentify emotions from eyebrow-obscured photographs compared to middle school (MS) adolescents (12-14 years) and adults (21+ years). Finally, US adolescents took significantly longer (> 5 seconds) to identify emotion from eyebrow-obscured photographs of the human visage compared to US adolescents shown the same unaltered control photographs. Therefore, the age group studied that is at most risk of facial misinterpretation and delayed response to facial cues which help foster interpersonal relationships are US adolescents.