Abstract
Recent developmental studies provided evidence that a few months of experience can be sufficient to induce preference for own race faces in young infants (Kelly et al., 2005; Bar-Haim et al., 2006). The aim of the present study was to explore the effect of facial experience on the development of face discrimination skill in infancy. Specifically, we examined the face discrimination ability of Japanese infants using Japanese faces and Caucasian faces.
A total of 48 Japanese infants aged 3–4 and 7–8 months participated in the present study. The guardians of these infants reported that infants had little or no experience with Caucasian people in their daily life. Stimuli were monochromatic pictures of female Japanese/ Caucasian faces with the same hair style. Half of the infants at each age group were assigned randomly to the Japanese face discrimination condition, and the rest of the infants were assigned to the Caucasian face discrimination condition. Infants were familiarized with a face for 60 seconds, and then were shown a familiar face and novel face side by side. In this paradigm, we infer that infants have discriminated between the faces, if they show a preference for the novel face.
Both the 3–4 and 7–8 month old infants showed a significant preference for a novel face in the Japanese face condition, but showed no preference in the Caucasian face condition. These results suggest that Japanese infants in both age groups discriminated only Japanese faces. Our findings are consistent with previous studies that found preference for own race faces in 3-month-olds (Kelly et al., 2005; Bar-Haim et al., 2006), and that found better recognition of own race face in 3-month-old Caucasian infants (Sangrigoli & De Schonen, 2004). We will provide further data from additional experiments that systematically changed discriminability of the faces using morphing technique.
We would like to thank Dr. Hiroshi Yamada for providing us with images of Japanese faces collected for the face database project at Nihon University (FIND). This study was supported by RISTEX and PRESTO, Japan Science and Technology Agency, and by a Grant-in-Aid for scientific research (18000090) from the Japan Society for the Promotion of Science.