Jean Piaget, a renowned Swiss psychologist, proposed a theory of cognitive development that outlines four stages which individuals must pass through to develop full human intelligence. These stages are:
- Sensorimotor Stage (0-2 years)
- Preoperational Stage (2-7 years)
- Concrete Operational Stage (7-11 years)
- Formal Operational Stage (12+ years)
Each stage is characterized by different ways of thinking and understanding the world.
1) Sensorimotor Stage (0-2 years)
In the sensorimotor stage, from birth to 2 years old, infants develop their senses and motor skills. They experience the world through movement and their five senses: seeing, hearing, smelling, tasting, and touching. Initially, infants rely on simple reflexes, but soon they begin to form habits. By around four months, they become aware of objects beyond their own bodies and start performing actions intentionally.
A critical milestone in this stage is the development of object permanence. Before achieving this, infants believe that objects cease to exist when they are out of sight. For instance, if a mother hides a teddy bear, the child thinks it has disappeared. After developing object permanence, they understand that the teddy bear still exists even when not visible.
During this stage, children are curious about their environment, wanting to explore and interact with everything around them. They begin to crawl, stand, walk, and eventually run, which enhances their cognitive development. However, they remain egocentric, perceiving the world only from their own perspective.
2) Preoperational Stage (2-7 years)
In the preoperational stage, children’s thinking is dominated by symbolic functions and intuitive thoughts. They engage in pretend play and believe that inanimate objects are alive. This stage is called preoperational because children are not yet capable of performing mental operations. They learn to speak and understand that words, images, and gestures symbolize other things.
Children enjoy role-playing, which helps them learn and develop. By age four, they become highly curious and ask numerous questions, marking the birth of primitive thinking. Piaget referred to this period as the “intuitive phase” because children have vast knowledge but don’t understand how they acquired it.
During this stage, children are still egocentric, believing that others see the world as they do. They struggle to understand different perspectives.
3) Concrete Operational Stage (7-11 years)
In the concrete operational stage, children discover logic and develop concrete cognitive operations, such as sorting objects. They begin to think inductively, drawing general conclusions from specific observations. They also grasp the concept of conservation—understanding that the quantity of a substance remains the same despite changes in its shape or container.
For example, children understand that pouring orange juice from a regular glass into a taller one doesn’t change the amount of juice. They also learn that mathematical operations can be reversed (e.g., if 3 + 5 = 8, then 8 – 3 = 5).
During this stage, children’s brains start organizing thoughts, classifying objects, and building concrete operational thinking structures. They begin to understand that their thoughts and feelings are unique and not necessarily shared by others, leading to the ability to empathize and see things from others’ perspectives.
4) Formal Operational Stage (12+ years)
As teenagers enter the formal operational stage, they develop the ability to think rationally about abstract concepts and hypothetical situations. They understand abstract ideas such as success, failure, love, and hate. This stage also involves forming a deeper understanding of identity and morality.
Teens can now think deductively, comparing statements and drawing logical conclusions. They can plan systematically and set priorities, making assumptions about events that may not be grounded in reality. They also start to philosophize and contemplate abstract concepts.
The newfound sense of identity can lead to egocentric thoughts, with some teens imagining an audience constantly watching them. While Piaget believed in lifelong learning, he insisted that the formal operational stage is the final phase of cognitive development.