Introduction. Anecdotally, Caucasians raised with no Asian contact sometimes report they cannot reliably recognise Asian faces no matter how hard they try, and no matter how much experience they obtain with Asian colleagues as adults. There is also formal evidence – from studies of perceptual narrowing in infancy (eg., Pascalis et al, 2002) and adults' ability to learn infant faces (Macchi Cassia et al., 2009) – to suggest contact at an early age may be crucial to maintain, or allow adult reactivation of, the ability to individuate all face types. But, just how “early” must exposure be? Language learning studies imply perceptual narrowing for nonexperienced languages in infancy is followed by a relatively lengthy period of retained plasticity that extends throughout primary school. Here, we test whether face recognition follows a similar course. Methods. Testing Caucasian adults, we used the unusual demographics and immigration history of Australia to dissociate effects of contact at different developmental stages: as babies, at primary school, at high school, and as adults. We measured both the ‘other-race’ effect on memory (difference between own-race and other-race faces) and the ‘other-ethnicity’ effect (difference between British-heritage Caucasian faces typical in Australia, and American Caucasian faces from the Harvard Face Database). Tasks were the Cambridge Face Memory Test and Chinese-face and Australian/British face variants. Subjects reported multiple contact variables (e.g., percentage of nonBritish Caucasians in their classes). Results. Contact in adulthood or at high school showed no correlations with either the other-race or other-ethnicity effects. Contact as a baby/toddler and in primary school each correlated with the other-ethnicity effect. (Currently, we have too little variation in early Asian exposure to address the equivalent question for the other-race effect.) Conclusion. Plasticity of face recognition is present in early childhood but disappears in adolescence and adulthood.
Supported by Australian Research Council DP0770923 and DP0984558.