Abstract
Most people are experts at recognizing faces and process faces holistically. While individual differences have been observed for the magnitude of holistic face processing, observers generally recognize faces of their own race or age groups better than faces of a different race or age group. It has been suggested that holistic processing is enhanced by increased visual experience and is driven by bottom-up sensory information. However, recent findings revealed mixed evidence that high-level socio-cognitive influences, such as arbitrary assignment of faces to in- vs. out-groups, may also modulate holistic processing. To further investigate socio-cognitive influences on face perception, we examined the effect of implicit social attitude on holistic face processing. While observers may not be consciously aware of their implicit social attitudes towards an out-group, the biases are often consistent across time within individual observers and might potentially influence behavior. Here we used images of infants, a group that the participants (n=59) had little experience with. Holistic processing for infant and adult faces was measured in a composite task; implicit social attitude towards infants and adults was measured in an implicit association test. We found that holistic processing, indicated by the congruency effect, was observed for both infant and adult faces at the group level. Among individual participants, implicit biases towards infants ranged from positive to negative. Critically, a significant correlation was observed between the magnitude of implicit social attitude for infants and the magnitude of holistic processing for infant faces (r=.26, p=.047), revealing stronger holistic processing with increased positive implicit social attitude. This finding suggests that individual differences on holistic processing, at least for faces of an ‘other’ group, are modulated by implicit social attitude. Taken together, holistic processing is unlikely a mere bottom-up perceptual effect, and high-level socio-cognitive processes can influence face perception.