This module looks at major theories, including Piaget’s, about how intelligence develops over time, and explores enduring questions such as how nature and nurture interact to produce lifespan cognition development, whether it is continuous or discontinuous, and ways that research in this area can be used to improve education.
What is Cognitive Development?
Cognitive development is a complex construct involving many different skills that grow and change over time. These skills include perceiving and acting skillfully on objects, language, motor, social-emotional, and cognitive domains of learning.
Piaget was the first to brand this type of research and study as “cognitive development.” His theory posits that children move through specific stages in their intellectual development. His stages are based on the relationship between biological maturation and children’s interaction with their environment.
Other theories on cognitive development posit core systems of cognition that are innately sensitive to certain kinds of information. These ideas are often referred to as empiricist and nativist frameworks. But despite these philosophies, much current cognitive developmental research shows that cognitive abilities are not innately acquired. For example, an experiment involving 3- to 6-year-olds found that children do not understand the difference between appearance and reality – even when a cat wearing a dog mask is present. Rather, children learn to distinguish between the two with experience, such as when they engage in dramatic play and use their new ability to represent objects in a variety of ways.
Piaget’s Theory
Piaget’s work paved the way for many others to study cognitive development. He developed a stage theory of child cognitive development and conducted detailed observational studies to reveal different levels of cognitive ability.
Piaget believed that children take an active role in creating knowledge and intelligence and that cognitive development occurs in stages. He called the basic mental structures that a child creates to understand the world “schemas.” These schemas are like a foundation on which kids build their understanding of the world.
He proposed four stages of cognitive development: sensorimotor, preoperational, concrete operational, and formal operational. These stages roughly correspond to specific ages from birth to adulthood. Piaget believed that children move through these stages at the same rate regardless of their cultural background and biological maturation.

His ideas were influential enough that educational curricula are often designed to align with the stages of cognitive development. However, Piaget’s stages were not without critics. For example, when researchers hid counters in children’s toys and asked them to find them, only 65% passed the test, suggesting that some children were still egocentric at this age (Piaget also failed to distinguish between competence and performance). Also, Piaget did not take into account the influence of culture on cognitive development.
Kohlberg’s Theory
Lawrence Kohlberg built upon Piaget’s cognitive theory of moral development and incorporated elements of other theories into his own. Like Piaget, Kohlberg believed that most moral development occurs through social interaction. His theory takes a discussion approach, focusing on how people think about moral issues rather than on specific values and principles. This avoids issues such as secular versus religious value systems, the problem of indoctrination and the issue of moral relativism.
Kohlberg identified six stages of moral development that span from childhood to adulthood. The first stage, preconventional morality, focuses on rules and punishment. For example, kids in this stage may think that stealing is bad because it violates the law and can lead to prison time.
The final stage, post-conventional morality, focuses on abstract reasoning and universal principles of ethics. For example, this stage could include an understanding of equal rights and a recognition of the role that personal merit plays in one’s career or success. Kohlberg also proposed a seventh stage of morality, called the Morality of Cosmic Orientation or Transcendental Morality.
The Web of Development
Cognitive development is one of the most fascinating areas of human inquiry. While seminal theories in this domain have emphasized linear, stage-based perspectives on cognitive development, new research has opened up several domains to explore, including how concepts develop; how children form and use mental models of their environment; and how knowledge evolves through processes such as problem solving, reasoning, and memory. This module introduces you to the major theories of cognitive development and addresses such enduring questions as whether cognitive development is continuous or discontinuous; how nature and nurture work together to produce cognitive development; and how cognitive developmental research is being used to improve education.
To capture this complexity, researchers have begun to think of cognitive development not as a ladder but as a web. This metaphor reflects the fact that skills evolve along independent strands in different domains, and that these strands are linked to one another and exert bidirectional influences on each other. The web also suggests that cognitive development is dynamic, with children moving both forward and backward along these strands and occasionally reshaping earlier skills to create new ones.