Formal Operational Stage of Cognitive Development

Formal Operational Stage
The formal operational stage begins at the onset of adolescence and lasts through adulthood.. Prasit photo / Moment / Getty Images

The formal operational stage is the fourth and final stage of Piaget's theory of cognitive development. The emerging abstract thought and hypothetical reasoning mark this phase of development. 

At this point in development, thinking becomes much more sophisticated and advanced. Kids can think about abstract and theoretical concepts and use logic to come up with creative solutions to problems.

Learn more about some of the essential characteristics and events that take place during this stage of cognitive development.

Characteristics of the Formal Operational Stage

  • The formal operational stage begins at approximately age twelve and lasts into adulthood.
  • During this time, people develop the ability to think about abstract concepts.
  • Skills such as logical thought, deductive reasoning, and systematic planning also emerge during this stage.

How Did Piaget Test Formal Operations?

Piaget tested formal operational thought in a few different ways:

One task involved having children of different ages balance a scale by hooking weights on the each end. To balance the scale, the children needed to understand that both the heaviness of the weights and distancing from the center played a role.

Younger children around the ages of 3 and 5 were unable to complete the task because they did not understand the concept of balance. Seven-year-olds knew that they could adjust the scale by placing weights on each end, but failed to understand that where they put the weights was also important.

By age 10, the kids considered location as well as weight but had to arrive at the correct answer using trial-and-error. It wasn't until around age 13 that children could use logic to form a hypothesis about where to place the weights to balance the scale and then complete the task.

In another experiment on formal operational thought, Piaget asked children to imagine where they would want to place a third eye if they had one.

Younger children said that they would put the imagined third eye in the middle of their forehead. Older children, however, were able to come up with a variety of creative ideas about where to place this hypothetical eye and various ways the eye could be used. An eye in the middle of one's hand would by useful for looking around corners. An eye at the back of one's head could be helpful for seeing what is happening in the background. Such creative ideas represent the use of abstract and hypothetical thinking, both important indicators of formal operational thought.


Piaget believed that deductive reasoning became necessary during the formal operational stage. Deductive logic requires the ability to use a general principle to determine a particular outcome. Science and mathematics often require this type of thinking about hypothetical situations and concepts.

Abstract Thought

While children tend to think very concretely and specifically in earlier stages, the ability to think about abstract concepts emerges during the formal operational stage.

Instead of relying solely on previous experiences, children begin to consider possible outcomes and consequences of actions. This type of thinking is important in long-term planning.


In earlier stages, children used trial-and-error to solve problems. During the formal operational stage, the ability to systematically solve a problem in a logical and methodical way emerges. Children at the formal operational stage of cognitive development are often able to plan quickly an organized approach to solving a problem.

Other Characteristics of the Formal Operational Stage

Piaget believed that what he referred to as "hypothetico-deductive reasoning" was essential at this stage of intellectual development. At this point, teens become capable of thinking about abstract and hypothetical ideas. They often ponder "what-if" type situations and questions and can think about multiple solutions or possible outcomes.

While kids in the previous stage (concrete operations) are very particular in their thoughts, kids in the formal operational stage become increasingly abstract in their thinking. They also develop what is known as metacognition, or the ability to think about their thoughts as well as the ideas of others.

Observations About the Formal Operational Stage

  • "The formal operational thinker has the ability to consider many different solutions to a problem before acting. This greatly increases efficiency, because the individual can avoid potentially unsuccessful attempts at solving a problem. The formal operational person considers past experiences, present demands, and future consequences in attempting to maximize the success of his or her adaptation to the world."
    (Salkind, 2004)​
  • "In the formal operational stage, actual (concrete) objects are no longer required and mental operations can be undertaken 'in the head' using abstract terms. For example, children at this stage can answer questions such as: 'if you can imagine something made up of two quantities, and the whole thing remains the same when one quantity is increased, what happens to the second quantity?' This type of reasoning can be done without thinking about actual objects."
    (Brain & Mukherji, 2005)

More From This Series:


Brain, C., & Mukherji, P. (2005). Understanding child psychology. United Kingdom: Nelson Thornes.

Piaget, J. (1977). Gruber, H.E.; Voneche, J.J. eds. The essential Piaget. New York: Basic Books.

Piaget, J. (1983). Piaget's theory. In P. Mussen (ed). Handbook of Child Psychology. 4th edition. Vol. 1. New York: Wiley.

Salkind, N. J. (2004). An introduction to theories of human development. Thousand oaks, CA: Sage Publications, Inc.

Santrock, John W. (2008). A topical approach to life-span development (4 ed.). New York City: McGraw-Hill.

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