Body Part Structure Knowledge in Infancy
Human faces, bodies, and hands convey critical social information (e.g., emotions, goals, and desires). Infants, like adults, are sensitive to such social information. Unlike infants' knowledge of the structure of the human face and body, not much is known about infants' knowledge of hands and feet. The current study tested infants for their preference between intact hand images and ones in which the same hands were distorted (i.e., location of at least one finger was altered to distort the
... to distort the typical structure of the hand). Infants at 3.5 months of age had a preference for the reorganized hand image, demonstrating that 3.5-month-olds have sufficient knowledge of the configural properties of hands to discriminate between intact versus distorted images. Furthermore, when the same images were inverted, infants displayed no such preference, indicating that infants were not relying solely on low-level features to detect differences between intact versus reorganized hands. Contrastingly, when shown images of intact and reorganized feet, even 9-month-olds did not exhibit evidence of sensitivity to structural disruptions in images of feet. These results indicate that infants' structural knowledge of hands, but not necessarily feet, develops along the same trajectory as their knowledge of faces and bodies.