- Formal Operational Stage (11 - 15 years) (Piaget) : Formal Operational Stage refers to the 3rd of the four (4) stages Piaget uses to define cognitive development. It begins at approximately 11 to 12 years of age, and continues throughout adulthood.
The formal operational stage is characterized by the ability to formulate hypotheses and systematically test them to arrive at an answer to a problem; thought becomes more abstract, incorporating the principles of formal logic, the ability to generate abstract propositions, multiple hypotheses and their possible outcomes is evident; thinking becomes less tied to concrete reality; prepositional logic, as-if and if-then steps; and use aids such as axioms to transcend human limits on comprehension.