Individual recognition of monkey (Macaca fuscata) and human (Homo sapiens) images in primatologists.

How experience affects the flexibility of facial identity recognition in adulthood is not fully understood. Primatologists are an interesting type of participants investigating facial identity recognition ability and flexibility because they can recognize individual primates based on their appearance, including body and facial features, through intense training during adulthood. Consequently, this study investigates the influence of primatological experience on individual recognition ability using eye-tracking techniques and sequential 2-alternative forced-choice matching tasks with images of humans (Homo sapiens) and Japanese macaques (Macaca fuscata). Results indicated that primatologists recognized faces of Japanese macaques more accurately than did control participants, while both primatologists and control participants recognized humans' faces with high accuracy. Primatologists demonstrated better recognition of monkey images when the whole body was presented than when only the face was presented, whereas control participants did not. Compared to the control participants, primatologists looked at areas other than the monkeys' faces for a longer time when whole-body images were presented. Furthermore, primatological experience (including study period and a total number of recognizable subjects in their studies) was related to the extent to which individual recognition of monkeys depended on nonface information. Altogether, our findings indicate that primatological experience improves the viewer's ability to recognize monkeys' faces. In addition, if available, primatologists with more experience studying monkeys use information from other parts of the body to recognize individual monkeys. (PsycInfo Database Record (c) 2021 APA, all rights reserved).