Two experiments investigated why perceptual pretraining facilitates children's performance on concept problems involving a nonpreferred relevant dimension and preferred irrelevant dimensions. (JMB)

Four experiments assessed converging aspects of four-month-old infants' perceptions of visual patterns. Results together corroborate and extend previous findings that vertical symmetry has a special status in early perceptual development and that infants can perceive pattern wholes. (Author/AS)

The hypothesis that overall-similarity relations structure both adults' and children's classifications of heterogeneous objects (objects that differ in a variety of ways) was supported in two experiments. When objects varied simultaneously on many dimensions, adults and children constructed classifications that maximized within-category similarity…