Research suggests that, using representations from object-based attention, infants can represent only 3 individuals at a time. For example, infants successfully represent 1, 2, or 3 hidden objects, but fail with 4 ("Developmental Science" 6 (2003) 568), and a similar limit is seen in adults' tracking of multiple objects (see "Cognitive Psychology"…

Three experiments examined the exclusivity of perpetually defined categorical representations for animal categories in infants. Results indicated that infants have the capacity for making distinctions among high similar natural kinds but that such find distinctions cannot be made without appropriate exemplars. (SW)