The preoperational stage is a developmental phase in which kids learn to represent things in the mind.

The preoperational stage is known as the second stage in Piaget’s theory of cognitive development. This stage starts around age 2, as kids start to talk, and lasts until age 7.

In this stage, kids start to engage in symbolic play and learn to manipulate symbols.  Piaget noted that they do not yet comprehend concrete logic.

Central Characteristics

The preoperational stage happens between the ages of 2 and 7. Language development is one of the milestones of this period.

Piaget noted that kids in this stage do not yet comprehend concrete logic, cannot mentally manipulate info, and are unable to assume the point of view of other people, which he called egocentrism.

In the preoperational stage, kids also become adept at using symbols, as evidenced by the increase in imaginary play. For instance, a kid is able to use an object to represent something else, like pretending a broom is a horse.

Role-playing also becomes essential— kids often play the roles of “mommy,” “daddy,” “doctor,” and other characters.

Understanding Egocentrism

Jean Piaget used several techniques to study the mental abilities of kids. One of the famous techniques to illustrate  egocentrism involved using a three-dimensional display of a mountain scene.  Kids are asked to select an image that showed the scene they had viewed.

Many kids can do this without difficulty. Next, kids are asked to select a image showing what someone else would have observed when viewing the mountain from a different vantage point.

Kids almost always select the scene showing their own view of the mountain scene. Kids experience this issue because they cannot consider another person’s vantage point.

Modern researchers have also conducted comparable experiments. In one study, kids were shown a room in a small dollhouse. Kids were able to see in the dollhouse that a toy was hidden behind a single piece of furniture. Kids were then taken into a full-size room that was a replica of the dollhouse. Young kids did not know that they needed to look behind the couch to find the toy, while older kids searched for the toy immediately.

Developmental psychologists refer to the capacity to comprehend that other people have different perspectives, thoughts, etc.  as theory of mind.

Understanding Conservation

Another famous experiment involves demonstrating a kid’s understanding of conservation. In one experiment, equal amounts of liquid are poured into two twin containers. Liquid in one container is poured into a cup that is shaped differently, like a tall and thin cup or a short and wide cup. Kids are then asked which cup holds the most liquid. Despite seeing that the liquid amounts were exactly the same, kids typically always select the cup that appears fuller.

Jean Piaget conducted several comparable experiments on the conservation of number, length, mass, weight, volume, and quantity. He found that few kids showed any comprehension of conservation before the age of five.

As you may have noticed, much of Piaget’s focus at this stage of development focused on what kids can not yet do. The ideas of egocentrism and conservation are centered on abilities that kids have not yet developed; they lack the understanding that things appear different to other people and that objects can change  while still maintaining their original properties.

Not everyone agrees with Piaget’s evaluation of kids’ abilities. Many researchers believe that his experiments and theories of child development were inherently flawed.