What is Piaget’s Theory of Development?
Jean Piaget proposed four stages of cognitive development. These stages help teachers assess and best serve students in the classroom. That is, if we can discern that a student is significantly over or under-developed with regard to their particular phase of development, we can seek out support for that child. We can also work with children who are in a transitional phase from one stage to the next. When we understand what their next stage is supposed to entail, we can help them master those skills or abilities.
The four stages are:
- Sensorimotor 18-24 months
- Preoperational 18 months to 2 years
- Concrete Operational 7 years to age 11
- Formal Operational approximately age 11 through the rest of life
What Are the Four Stages?
Sensorimotor
The sensorimotor stage begins at birth and lasts until around 18-24 months. In this pre-linguistic stage, infants develop simple motor skills and adapt to their environment. Early on, they don’t realize that objects continue to exist when out of sight, but a key milestone is the development of object permanence—the understanding that objects remain in place even when not visible.
As they grow, infants learn to navigate their world through actions like rolling over, crawling, and walking. Around the time they start walking, they also begin to use language to represent objects and ideas. For example, once a child understands that food remains in the cupboard, they may start asking for it. This marks the transition to the next developmental stage.
Preoperational
The Preoperational Stage begins around age 18 months to two years and lasts until about age seven. During this time, children’s language skills develop rapidly, and their imagination and abstract thinking also advance. As they interact more with adults and peers, their expressions and social behaviors become more mature.
However, children in this stage lack strong logic skills and struggle with concepts like time, distance, and comparisons. They also have difficulty solving problems mentally and still rely on physical representations. Additionally, they are egocentric, meaning they struggle to see things from others’ perspectives, which can sometimes lead to behavior that seems cruel. This egocentrism typically fades as they grow.
Concrete Operational
The Concrete Operational Stage, occurring from about age seven to 11, is characterized by the ability to think logically and solve problems mentally. Children develop the concept of conservation, understanding that an object’s quantity remains the same even if its appearance changes, such as when the same volume of water fills both a tall, narrow and a short, wide container.
During this stage, children also become less egocentric. They start recognizing that their thoughts and feelings are personal and not shared by everyone, and they become more aware of how others might experience events and situations that don’t directly involve them.
Formal Operational
The Formal Operational Stage, Piaget's final stage, begins around age 11 and continues throughout life. It is marked by the ability to think abstractly, consider hypothetical situations, and test those ideas. People can also see how different concepts or objects relate to one another, leading to a broader sense of possibility.
While this is Piaget’s last stage of cognitive development, human cognition continues to evolve. By this point, individuals have the core abilities needed to navigate the world, and from age 11 onward, they continue to adapt and grow in response to new challenges.
How Can Teachers Use This?
Developmental theories are central to how teachers approach their classrooms, and teacher-prep programs include courses on childhood development to ensure educators understand where students are in terms of psychological growth. While many theories focus on emotional and social development, Piaget's model stands out for its emphasis on cognitive development, specifically how we process information and adapt to learn new concepts throughout life.
In the classroom, Piaget’s concepts of assimilation and accommodation can help teachers introduce new material by relating it to what students already know. Achieving "equilibrium" allows students to move forward in their learning.
Teachers should also be mindful of their students' developmental stages. For younger children in the Sensorimotor Stage, teachers can focus on recognizing shapes and colors. For those in the Preoperational Stage (roughly Preschool to grade 2), teachers should understand that students’ thinking is still egocentric and intuitive. Lessons should be adapted to this stage, gradually introducing abstract thinking and non-egocentric concepts.
For students in the Concrete and Formal Operational stages, teachers can assess where students are in their cognitive development and design lessons that build on their existing skills, helping them transition to more complex knowledge and thinking.
Criticism
Piaget's theory of cognitive development has faced several criticisms, particularly regarding his research methods, sample bias, and underestimation of children's abilities. His work was based on a small, unrepresentative sample of his own children and their peers, all from privileged backgrounds. Additionally, Piaget didn’t clearly define his variables, making his study difficult to replicate, which is a key criterion for validating research.
The theory has also been criticized for underestimating children's cognitive abilities. For example, Piaget claimed that children in the Preoperational Stage are egocentric and unable to understand others' perspectives, but later research has shown that children as young as three can demonstrate non-egocentric thinking.
Terminology
One key part of Piaget's theory of cognitive development is his emphasis on adaptation. That is, he saw that young people did not yet have the tools that were available to fully developed adults. Rather, children undergo a lengthy process in which they find moments of disequilibrium with their world but then apply old lessons, schema to Piaget, to assimilate the new information or situation.
- Schema
Piaget's cognitive theory posits schemas as the core of one's ability to build mental models of the world. As we develop, our schemas become more intricate, detailed, and numerous. We have schemas to help us navigate our lives. For instance, one's schema for commuting to work would involve things like starting and driving a car, boarding a train, and navigating a route. Within each of these basic stages we have sub-schema such as shifting gears, purchasing a ticket, reading a map, using alternate routes, etc. Initially, schemas are simple, focusing on basic behaviors and sensory details, but by around 18 months, they evolve to include more complex systems and relationships.
- Assimilation
In Piaget's theory, assimilation is part of adaptation. It involves incorporating new information into preexisting schemas to understand it. For example, knowing French can help someone understand Spanish, as the two languages share similarities. Assimilation occurs regularly in daily life, such as when we try new foods, drive unfamiliar cars, or meet new people.
- Accommodation
Accommodation is another vital part of adaptation. In the example above, a traveler to Spain might rely on their knowledge of the French language to navigate the new culture. However, while French and Spanish have many things in common, they will still have to adapt their schema so that they can learn the nuances of Spanish. Similarly, game players change their strategies to meet the unique demands of a new opponent or game.
- Equilibrium
In Piaget's developmental theory, the need for equilibrium is what drives cognitive development. That is, when a person encounters a new situation that cannot be easily assimilated, disequilibrium occurs. This triggers frustration and other negative emotions until the new information can be accommodated/assimilated. Once a person adapts to the new situation, growth and development occur.
How Piaget’s Philosophy & Work Has Helped
Although much of Piaget's work has been challenged by later research, it remains valuable, especially for psychologists and educators. His theories are still taught in Human Development courses, not so much for their scientific accuracy but for his pioneering contributions.
Piaget made a significant breakthrough by recognizing that children are distinct from adults. Prior to his work, psychology treated children as small adults. His identification of developmental stages in children's cognitive growth has had a lasting impact, emphasizing the need for adults to understand these stages to foster healthy development.
Piaget’s methodology, though flawed, was also revolutionary. He conducted in-depth interviews with his subjects, a technique not previously used, and set the stage for modern research where individuals are asked to analyze their own thinking.