which psychologist was most influential in shaping our understanding of cognitive development?
What he was more interested in was the way in which fundamental concepts like the very idea of number, time, quantity, causality, justice and so on emerged. Piaget (1936) was the first psychologist to make a systematic study of cognitive development. His contributions include a stage theory of child cognitive development, detailed observational studies of cognition in children, and a series of simple but ingenious tests to reveal different cognitive abilities.