Quinn (2004) reported that the asymmetry in categorization of humans versus nonhuman animals by human infants (i.e., a representation for humans that includes nonhuman animals vs. a representation for nonhuman animals that excludes humans) was based on holistic information. The current research investigated how this asymmetry was affected by stimulus inversion. Three- to 4-month-olds were familiarized with humans or cats and then tested with a novel cat versus a novel human in upright and inverted presentation conditions. Only the human portion of the asymmetry was affected by inversion, implying that only the upright human familiarization condition engaged configural processing. The findings are consistent with the idea that differences in the way that infants process humans versus nonhuman animals can be likened to an expert-novice distinction in the early development of perceptual category representations.
KEYWORDS: categorization, perceptual expertise, configural processing, infants.