ИСТИНА

The perception of facial symmetry is generally considered in comparison with the assessment of facial attractiveness, while far fewer studies have focused on symmetry perception mechanisms. For instance, the perception of symmetry has been shown to be affected by inversion (Rhodes et al., 2005; Luniakova, Kurenkova, 2023). This study explores whether familiarity of a face influences how symmetrical it looks. The sample included 30 people (25 classmates and 5 teachers). All participants have known each other for over 5 years and meet regularly. Black-and-white neutrally expressed full face photographs were used as stimuli (20 images of participants’ faces and 20 images of unfamiliar faces). Overall facial asymmetry (Penton-Voak et al., 2001) was calculated for each face image, and the distribution of facial asymmetry index was similar in groups of «familiar» and «unfamiliar» faces. Prior to enrolment in the study, all participants had given written consent. The photographs of original faces and their horizontally mirrored versions, totalling 160, were presented to the participants one by one for 2000 ms each. The participants had to rate the asymmetry of the presented faces on a ten-point scale. Self-face photo ratings were excluded from the analysis. Wilcoxon signed rank test revealed a significant difference in the ratings of the original and the mirror images of familiar faces (n = 588, Z = 3.78, p < 0.001), while there was no difference between the ratings of the original and the mirror images of unfamiliar faces (n = 600, Z = 0.99, p = 0.318). The results showed that familiarity of a face influences perception of its symmetry. Mirror images of familiar faces are perceived as more asymmetrical than the original faces, although the objective parameters of facial symmetry remain unchanged. No such trend was found for unfamiliar faces.