The Preoperational Stage
Preschool-age children (ages 3–5) make steady progress in cognitive development. Not only can they count, name colors, and tell you their name and age, but they can also make some decisions on their own, such as choosing an outfit to wear.
Preschool-age children understand basic time concepts and sequencing (e.g., before and after), and they can predict what will happen next in a story. They also begin to enjoy the use of humor in stories. Because they can think symbolically, they enjoy pretend play and inventing elaborate characters and scenarios. One of the most common examples of their cognitive growth is their blossoming curiosity. Preschool-age children love to ask “Why?”
the preoperational stage
Piaget’s second stage is the preoperational stage, which lasts from approximately 2 to 7 years old. In this stage, children can use symbols to represent words, images, and ideas, which is why children engage in pretend play. A child’s arms might become airplane wings as they zoom around the room, or a child with a stick might become a brave knight with a sword.
Symbolic Thinking and Language Development
Children begin to use language extensively during the preoperational stage, but they cannot yet understand adult logic or mentally manipulate information. The term operational refers to logical manipulation of information, so children at this stage are considered pre-operational.
Children’s logic is based on their own personal knowledge of the world so far, rather than on conventional knowledge.
Imagine Dad gave a slice of pizza to 10-year-old Keiko and another slice to her 3-year-old brother, Kenny. Kenny’s pizza slice was cut into five pieces, so Kenny told his sister that he got more pizza than she did. Kenny focused on the number of pieces rather than understanding that the total amount remained the same.
Lack of Conservation
Children in this stage cannot perform mental operations because they have not developed an understanding of conservation—the idea that even if you change the appearance of something, it is still equal in size as long as nothing has been removed or added.
You can view the transcript for “A typical child on Piaget’s conservation tasks” here (opens in new window).
Egocentrism
During this stage, children display egocentrism, which means they are not able to take the perspective of others. A child at this stage thinks that everyone sees, thinks, and feels just as they do.
Keiko’s birthday is coming up, so their mom takes Kenny to the toy store to choose a present for his sister. He selects an Iron Man action figure for her, thinking that if he likes the toy, his sister will too. An egocentric child cannot infer the perspective of other people and instead attributes their own perspective to others.
You can view the transcript for “Piaget’s Mountains Task” here (opens in new window)
Additional Characteristics of Preoperational Thought
- Centration: The tendency to focus on one aspect of a situation while ignoring others. For example, in conservation tasks, children focus on the height of liquid in a glass while ignoring its width.
- Irreversibility: Difficulty understanding that actions can be reversed. Preoperational children struggle to mentally reverse an action they have just witnessed.
- Animism: The belief that inanimate objects have lifelike qualities and are capable of action. A child might think the sun is happy or that a doll feels sad.
- Transductive reasoning: Reasoning from one specific instance to another specific instance, rather than from general to specific (deductive) or specific to general (inductive). For example, a child might reason, “I had a dog and it barked, so all dogs must bark.”
Theory of Mind: Understanding Others’ Mental States
At some point during the preoperational stage—typically between 3 and 5 years old—children come to understand that people have thoughts, feelings, and beliefs that are different from their own. This is known as theory of mind (ToM).
Theory of mind refers to the ability to attribute mental states to oneself and others—understanding that others have beliefs, desires, plans, and intentions that may differ from one’s own. This ability is essential for social interaction and communication.
Research shows that ToM develops in a predictable sequence during early childhood:
Ages 2-3: Children understand that people have desires and emotions
- They recognize that others may want different things
- They understand basic emotions in themselves and others
Ages 3-4: Children begin to understand that people have beliefs
- They recognize that people can have different knowledge
- They start to understand that seeing leads to knowing
Ages 4-5: Children develop understanding of false beliefs
- They recognize that others can believe something that is not true
- They understand that people’s actions are based on their beliefs, even when those beliefs are incorrect
False-belief tasks are useful in determining a child’s acquisition of theory of mind. These tasks assess whether children understand that others can hold beliefs that differ from reality.
Take a look at this video clip showing a false-belief task involving a box of crayons.
You can view the transcript for “The “False Belief” Test: Theory of Mind” here (opens in new window).
Current Research on Theory of Mind
ToM continues to develop well beyond age 5, with children showing increasing sophistication in understanding complex mental states through middle childhood and adolescence (Wellman et al., 2020; Erceg et al., 2025).[1]
Individual differences: Several factors influence the rate of ToM development:
- Language abilities: Children with more advanced language skills tend to develop ToM earlier
- Sibling relationships: Children with siblings, particularly older siblings, show earlier ToM development
- Parent-child conversations: Mothers who talk about thoughts, wants, and feelings promote earlier ToM understanding
- Pretend play: Participation in pretend play accelerates ToM development
- Cultural context: Children from different cultures may develop aspects of ToM at different rates or in different sequences
Social outcomes: Children with more developed theory of mind tend to be:
- Better communicators who can resolve conflicts with friends
- More popular with peers
- Rated as more socially competent by teachers
- Happier in school
- More advanced in some areas of schoolwork
However, well-developed ToM can also be used in antisocial ways, such as teasing, bullying, and lying.
Recent research using brain imaging has identified that neural sensitivity to others’ belief states in infancy predicts later ToM reasoning in childhood, suggesting biological foundations for this ability (Liu et al., 2025).
Contemporary Understanding
While Piaget’s preoperational stage provides a valuable framework, modern research suggests some refinements:
- Children may be less egocentric than Piaget proposed when tasks are simplified
- Some conservation understanding may emerge earlier than Piaget suggested
- ToM development is more gradual and continuous than Piaget’s stage theory implies
- Cultural and social factors play significant roles in cognitive development during this period
Despite these refinements, Piaget’s description of preoperational thought captures important differences in how young children think compared to older children and adults.
- Erceg HG, Dhillon RS, Derksen DG, Mah EY and Bernstein DM (2025) A longitudinal study of theory of mind across the lifespan. Front. Psychol. 16:1549378. doi: 10.3389/fpsyg.2025.1549378 ↵