JAPANESE TOP Message from the Director Information Faculty list Research Cooperative Research Projects Entrance Exam Visitors Publication Job Vacancy INTERNSHIP PROGRAM Links Access HANDBOOK FOR INTERNATIONAL RESEARCHERS Map of Inuyama
TOPICS
BONOBO Chimpanzee "Ai" Crania photos Itani Jun'ichiro archives Guidelines for Care and Use of Nonhuman Primates(pdf) Study material catalogue/database Guideline for field research of non-human primates 2019(pdf) Primate Genome DB

Primate Research Institute, Kyoto University
Inuyama, Aichi 484-8506, JAPAN
TEL. +81-568-63-0567
(Administrative Office)
FAX. +81-568-63-0085

Copyright (c)
Primate Research Institute,
Kyoto University All rights reserved.


Contact

Japanese

Facial colour is a more salient cue than shape for chimpanzees to differentiate infant and adult faces
Yuri Kawaguchi, Koyo Nakamura, Masaki Tomonaga
Abstract

Social primates must recognise developmental stages of other conspecifics in order to behave
appropriately. Infant faces have peculiar morphological characteristics-relatively large eyes, a small nose, and small mouth-known as baby schema. In addition, the infant faces of many primate species have unique skin coloration. However, it is unclear which features serve as critical cues for chimpanzees to recognise developmental changes in their faces. The present study aimed to investigate the relative contributions of facial shape and colour to age categorisation in chimpanzees. We used a symbolic matching-to-sample task in which chimpanzees were trained to discriminate between adult and infant faces. Then, we tested how their age category judgments transferred to a series of morphed faces which systematically differed in facial shape and colour. Statistical image quantification analysis revealed significant differences both in shape and colour between adult and infant faces. However, we found that facial coloration contributed to age categorisation in chimpanzees more than facial shape. Our results showed that chimpanzees use unique infantile facial coloration as a salient cue when discriminating between adult and infant faces. The display of their developmental stages through facial colour may help chimpanzees to induce appropriate behaviour from other individuals.



Research summary
Bibliographic information
Kawaguchi, Y., Nakamura, K. & Tomonaga, M.(2020). Colour matters more than shape for chimpanzees' recognition of developmental face changes. Scientific Reports, 10.
https://doi.org/10.1038/s41598-020-75284-2
2020/10/26 Primate Research Institute