Four experiments examined the perceptual features used by 4.5- to 11.5-month olds to individuate objects involved in occlusion events. Results indicated that 4.5-month olds used shape and size features to individuate objects in occlusion events. By 7.5 months, infants used pattern, and by 11.5 months, they used color to reason about object…

Wilcox (Cognition 72 (1999) 125) reported that infants are more sensitive to form than surface features when individuating objects in occlusion events: it is not until 7.5 months that infants spontaneously use pattern information, and 11.5 months that they spontaneously use color information, as the basis for object individuation. The present…