Piaget Stages of Development

Medically Reviewed by Jabeen Begum, MD on February 16, 2024
8 min read

Piaget's stages of development are part of a theory about the phases of normal intellectual development from infancy through adulthood, including thought, judgment, and knowledge. The stages were named after psychologist and developmental biologist Jean Piaget, who recorded and studied the intellectual development and abilities of infants, children, and teens.

Piaget's four stages of intellectual (or cognitive) development are:

  • Sensorimotor. Birth through 2 years old
  • Preoperational. Toddlerhood through early childhood (2-7 years old)
  • Concrete operational. Ages 7-11 years old
  • Formal operational. Adolescence through adulthood, 12 years and older

Piaget acknowledged that some children may pass through the stages at different ages than the averages noted above. He also said some children may show characteristics of more than one stage at a given time.

But he insisted that:

  • Cognitive development always follows this sequence.
  • Stages cannot be skipped.
  • Each stage is marked by new intellectual abilities and a more complex understanding of the world.

Piaget's 1936 theory broke new ground because he found that the brains of children work very differently than those of adults. Before his theory, many believed that children were not yet capable of thinking as well as grown-ups.

Some experts disagree with his idea of stages. Instead, they see development as continuous. Another criticism is that Piaget didn't consider how a child's culture and social environment can affect their development.

According to Piaget, at the start of the sensorimotor stage (0-2 years old), infants are only aware of what is right in front of them. They learn with their senses and motor skills, focusing on what they see and do (visual and physical interactions) within their immediate environment.

They're constantly experimenting because they don't yet know how things react. They shake or throw things, put things in their mouth, and learn about the world through trial and error. The later substages include goal-oriented behavior that leads to a desired result. For instance, they may cry to see if you’ll attend to them.

Between the ages of 5-8 months, infants begin to realize that an object exists even though they can no longer see it. This critical milestone, known as object permanence, is a sign that the child is developing memory. For example, the infant learns that when you leave, you still exist, and you’ll be back. They may also look for a toy when it’s not with them because they know it still exists.

They may also show stranger anxiety or fear of unfamiliar faces as they develop object permanence. They may cry and cling to parents or other familiar faces when strangers are around.

As infants start to crawl, stand, and walk, their increased physical mobility leads to more cognitive development. Near the end of the sensorimotor stage (18-24 months), infants reach another important milestone -- early language development -- a sign that they are developing some symbolic abilities.

During this stage (2-7 years old), children can think about things symbolically, like using symbols to represent words, things, pictures, people, and ideas. As a result of being able to think symbolically, they can also:

  • Mimic behavior (imitation). Your child may act as something else, even when the thing they’re modeling is no longer with them. For example, they may walk the way someone else walks, even when the person isn’t with them. They might use their arms to mimic airplane wings as they run around the room.
  • Play pretend or make-believe. Your child can imagine and pretend that an object is something else (symbolic representation). For example, a stuffed animal can become a baby, and they may act as the parent.
  • Draw. Drawing can start with scribbling and making images representing people and things in the child’s world. For example, stick drawings may represent family members, and round objects may represent toys.
  • Develop mental imagery. Your child creates their own mental images, and they may ask you for the names of things so they can better understand what they're thinking about and visualize it.
  • Describe events verbally. Explaining or imitating experiences with words shows your child can think and learn, not just react to their surroundings.

They may also engage in egocentric thinking, where they can’t understand that others think differently from them or see things from another person’s perspective.

At this time, elementary-age and preadolescent children, aged 7-11 years old, show logical, concrete reasoning. Children at this age gain the following skills:

  • Decentering: Children's thinking becomes less focused on themselves. They begin to realize their thoughts and feelings are unique and may not be shared by others or be part of reality. They also become more empathic. Experts also describe decentering as "theory-of-mind (TOM)."
  • Conservation: The child becomes aware of their surroundings and learns that things remain the same despite existing in a different form. For example, they know the amount of juice in its original bottle is still the same when poured into a glass cup. 
  • Reversibility: The child learns that things can return to their original state unchanged. For example, they learn that the juice poured into the glass cup can return to the bottle unchanged.
  • Class inclusion: The child can now group objects based on shape or type. 
  • Relations: The child can use logic to perceive and organize a series of gradually changing items, such as arranging objects by size.

But during this stage, most children still can't think abstractly or hypothetically.

Adolescents who reach this fourth stage of intellectual development -- usually around age 11 or older -- can use symbols related to abstract concepts, such as algebra and science. They can think about things in systematic ways, come up with theories, and consider possibilities. They also can think about abstract relationships and concepts such as justice.

Children in this stage may become even more self-conscious and magnify their experiences or circumstances over how others might. A child with a pimple might believe it is bigger than what it is and that others see it the way they do.

Although Piaget believed in lifelong intellectual growth, he insisted that the formal operational stage is the final stage of cognitive development. He also said that continued intellectual development in adults depends on the buildup of knowledge.

Along with the stages of development, Piaget's theory has several other key concepts.

Schemas are thought processes that are building blocks of knowledge. A baby, for example, knows that it must make a sucking motion to eat. That's a schema.

Assimilation is how you use your existing schemas to interpret a new situation or object. For example, a child seeing a skunk for the first time might call it a cat, or a baby may put everything they see in their mouth.

Accommodation happens when you change a schema or create a new one to fit new information you learn. The child accommodates when they understand that not all furry, four-legged creatures are cats.

Equilibrium happens when you can use assimilation to fit in most of the new information you learn into existing schemas. Only sometimes, you need to create new schemas.

Piaget's theory has influenced education and parenting. Here are some practical ways teachers and parents can put his ideas to work:

  • Remember that kids learn best by doing things rather than hearing about them. Learning to solve problems isn't something that can be taught. It must be discovered.
  • The learning process is as important (or more so) as the result.
  • Don't try to teach a child something they aren’t ready to learn. According to Piaget's stages, kids must master one level before they move on to the next.
  • Kids learn as much from each other as from parents or teachers. Give them projects to do together, as well as individual tasks.

While learning the skills, not all children follow the exact timeline outlined by Piaget's theory. Your child may develop at their own pace, and that’s not a cause for concern. Support them at every stage and allow them to learn and grow.

Although experts note that Piaget's stages of development can help you know what to expect from children at different ages, they also acknowledge that these stages don’t work the same way for everyone and may overlap. More recent research shows that a child moves away from egocentrism by 4-5 years, earlier than what Piaget suggested (7-11 years old).

Other shortcomings of Piaget’s theory include overestimating an adolescent's cognitive abilities, underestimating an infant’s, and overlooking how much cultural and social factors affect children’s thinking.

Experts also note that his findings were tainted by ethical issues and bias. His initial observations focused on his own children, and he didn’t document details about the socioeconomic background of other participants, or how many there were.

Piaget's stages of development group intellectual development from infancy through adulthood into phases. His theory has significantly influenced the science of child development and may help guide expectations regarding your child’s growth. Still, the four defined stages have limitations because they don’t reflect the experience of all children. Every child is unique, and their cognitive development may not precisely follow Piaget’s stages. Talk to your child's doctor if you have any concerns about their development at any age.

What are the four stages of Piaget's cognitive development?

Piaget's four stages of cognitive development are:

  • Sensorimotor. Birth through 2 years old, when babies start to understand object permanence.
  • Preoperational. Toddlerhood through early childhood (2-7 years old), when young children develop symbolic thought.
  • Concrete operational. Ages 7-11 years old, when kids display logical thought.
  • Formal operational. Adolescence through adulthood (12 years and older), when adults can use and understand scientific reasoning.

What is Piaget's theory of child development?

Jean Piaget’s theory of child development is that as we grow from infancy, the way we think and reason changes. He identified four stages starting with birth through adulthood: the sensorimotor stage (0-2 years old), preoperational stage (2-7 years old), concrete operational stage (7-11 years old), and formal operational stage (12 years and older).

What is the 5th stage of cognitive development?

Some researchers argue that a fifth stage, the postformal stage, should exist. This stage comes after the formal operational stage. In this stage, adults can:

  • See things from many perspectives.
  • Recognize and embrace uncertainties and inconsistencies.
  • Use their situation, circumstances, and experiences to make decisions and solve problems.
  • Develop principles guided by context, logic, and emotion.