Rochel Gelman has been a leader in the study of the thought processes of infants and young children. Her studies have been instrumental in showing that infants possess an understanding of numbers. Her work with children has demonstrated the impressive abilities of young children to count and to understand in a sophisticated way the basic principles of enumeration. Her book (with Gallistel) served as the basic source for a generation of developmental studies of the number skill and for the discussion and design of methods of instruction. She has also explored the development of other high level cognitive skills including music and language. She has been instrumental in training developmental psychologists to probe the secrets of infant and child mind.