The formal operational stage is the final stage of cognitive development in Jean Piaget's theory. It's characterized by the ability to think abstractly, solve problems, and reason hypothetically:
Abstract thinking
The ability to think about abstract concepts and relationships, like justice
Problem solving
The ability to use words, imagination, and hypothetical thinking to solve problems without physical objects or drawings
Reasoning
The ability to reason contrary to fact, like dealing with the statement "what would happen if snow were black"
Hypothetical thinking
The ability to formulate hypotheses and systematically test them to arrive at an answer to a problem
Logical deduction
The ability to apply reason to hypothetical and abstract objects and ideas