A number of studies have challenged aspects of Piaget's theory. Two examples are Diamond's (1985) study on infants' ability to reach for hidden objects and Gelman and colleagues' studies on preschoolers understanding of number

Review either Diamond's findings or Gelman's findings, and discuss how the findings challenge an aspect of Piaget's theory.

What will be an ideal response?

Diamond showed that infants' tendency to search for a hidden object is related to how long ago the object was hidden. As infants get older, they become able to search after longer and longer delays. Findings suggest that the ability to reach for hidden objects develops gradually, and they challenge Piaget's notion that cognitive change happens abruptly, in a stage-like fashion. Gelman and colleagues have shown that preschool children understand some aspects of the concept of number (e.g., they can count accurately, they understand the effects of the addition and subtraction of objects on a set of objects, they can identify which numbers in a set of numbers are larger and which are smaller). These studies challenge Piaget's claim that preschoolers do not understand the concept of number. More generally, they suggest that Piaget may have underestimated young children's capabilities.