Piaget found four major developmental stages (with many subdivisions). For the first year and a half or two years of life, infants are only aware of sensorimotor experience, and do not connect it ...

The sensorimotor stage is a time when ... Despite being over 70 years old, Piaget's theory is "still one of the prevailing theories in terms of cognitive development," Dr Sam Durrant explains.

By thinking that children have great cognitive abilities, Piaget came up with four different cognitive development stages, which he put out into testing. Within those four stages he managed to group ...