At What Age Is the Human Brain Cognitively Mature

Developmental biologist Jean Piaget laid the foundation for understanding human cognition by identifying distinct stages of intellectual development 1. (Reference 1) Subsequent study of the brain itself has essentially validated Piaget’s stage theory by showing the relationship between brain growth and cognition. (Reference 2)

Definition of Cognitive Maturity

Cognitive maturity implies more than the ability to calculate or memorize facts. Mature thinking includes using good judgment, understanding cause and effect, being able to associate current behavior with future consequences, and other thought processes associated with rational, socially acceptable behavior. (Reference 3)

Piaget’s Stages

Piaget defined four stages of development: sensory-motor (birth to 2 years), pre-operational (2 to 7 years), concrete operations (7 to 12 years) and formal operations (12 years and older). The capacity for logic and abstraction occurs only in the final stage, according to Piaget, and continues to develop throughout adolescence. (Reference 1)

Brain Development

Studies of the brain show periods of rapid growth, both in size and complexity, corresponding with the onset of each of Piaget’s stages. Periods of slower growth follow these growth spurts, allowing for practice and consolidation of new brain functions. (Reference 2) Brain development continues into the mid-20s, leading to cognitive maturity. (Reference 3)


Parental and societal expectations should be adjusted to take the realities of cognitive maturity into account. (Reference 3)

Important Fact

Individuals develop at differing rates, affected by genetic and environmental factors. (Reference 2)