Abstract
The aspects of facial attractiveness have been widely studied, especially within the context of evolutionary psychology, which proposes that aesthetic judgements of human faces are shaped by biologically based standards of beauty reflecting the mate quality. However, the faces of primates, who are very similar to us yet still considered non-human, remain neglected. In this paper, we aimed to study the facial attractiveness of non-human primates as judged by human respondents. We asked 286 Czech respondents to score photos of 107 primate species according to their perceived “beauty.” Then, we analyzed factors affecting the scores including morphology, colors, and human-likeness. We found that the three main primate groups were each scored using different cues. The proportions of inner facial features and distinctiveness are cues widely reported to affect human facial attractiveness. Interestingly, we found that these factors also affected the attractiveness scores of primate faces, but only within the Catarrhines, i.e., the primate group most similar to humans. Within this group, human-likeness positively affected the attractiveness scores, and facial extremities such as a prolonged nose or exaggerated cheeks were considered the least attractive. On the contrary, the least human-like prosimians were scored as the most attractive group. The results are discussed in the context of the “uncanny valley,” the widely discussed empirical rule.
Highlights
Faces play a key role in the identification of other individuals, which is one of the most important skills needed in social communication of primates (Pascalis and Bachevalier, 1998; Santana et al, 2012)
In our mainly exploratory study, we focused on the following two questions: (1) which factors determine the primate facial attractiveness rated by human respondents? (2) Do these determining factors differ among different primate groups? There are three main groups of primates: the prosimians, which are phylogenetically least related to us, the New World monkeys (Platyrrhini), and its sister taxon Catarrhini, which includes Old World monkeys, gibbons, great apes, and humans
To ensure that the knowledge of the great apes being the most phylogenetically related to humans did not distort the overall agreement, we checked for the intra-class correlation (ICC) of the data excluding the Homoidea: ICC was 0.983 for averagemeasure, 0.5 for single-measure; i.e., these analyses show that the respondents agreed well on the human-likeness of the particular primate groups/species and their rankings were not influenced by just the most human-like apes
Summary
Faces play a key role in the identification of other individuals, which is one of the most important skills needed in social communication of primates (Pascalis and Bachevalier, 1998; Santana et al, 2012). We are able to holistically distinguish faces that subtly differ in minimal position changes of inner facial features, i.e., the eyes, nose, and mouth (Maurer et al, 2002). We use this recognition ability when evaluating the facial attractiveness: the evaluation is very strict as minimal deviation from the averageness or subtle distinctiveness can be perceived as unattractive or attractive. The way in which humans consider attractiveness of faces of other species forms a very interesting question In this matter, primates represent the perfect group to study— they include species phylogenetically closest to humans with very human-like faces, and less similar species like the prosimians. Is it possible that human respondents see some primates as human caricatures and evaluate their facial attractiveness using the same facial cues as they use when evaluating facial beauty of conspecifics?
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
