The rational part of a teen's brain isn't fully developed and won't be until age 25 or so. In fact, recent research has found that adult and teen brains work differently. Adults think with the prefrontal cortex, the brain's rational part.

At what age does a child develop reasoning?

* By the age of 5 or 6, children begin to start understanding the problems and searching for ways to solve them; they begin to use logical reasoning. This is especially apparent as children of this age group begin to use speech as a basis for logical reasoning.

At what age does reasoning begin in human thinking?

Cognitive development means the growth of a child's ability to think and reason. This growth happens differently from ages 6 to 12, and from ages 12 to 18. Children ages 6 to 12 years old develop the ability to think in concrete ways.