Psychology. Term 3 Leo Raymond. Jean Piaget. Born: August 9, 1896 in Switzerland Died: September 16, 1980 (age 84) Known As: “Father of Child Psychology”. Jean Piaget. His theory of C ognitive Development is still used today. The 4 stages are:
Sensori-motor period (from birth until age 2)
Pre-operational stage (from 2-6)
Concrete operational stage (6-12)
Formal operational stage (12 and up)
The baby lacks object permanence.
people develop the ability to think about abstract concepts.