Sensorimotor

Birth to 2 years

Child’s interactions with the environment are based on sensory and motor systems; no logical operations occur.

Preoperational

2 to 7 years

Child can use mental symbols (words, numbers), yet still cannot perform logical operations.

Concrete operational

7 to 11 years

Child can perform logical operations on physical (“concrete”) objects.

Formal operational

11 years to adulthood

Child can perform operations on physical and hypothetical objects; he or she can also engage in abstract reasoning.