Cognitive Development

Intelligence is the ability to understand. According to psychologist Jean Piaget, intelligence develops gradually as a child grows. A 4-year-old cannot understand things a 7-year-old grasps easily. After years of studying children, Piaget concluded that young children think in a different way than older children and adults. As children's intelligence grows, the amount of information they know increases. Also, the way they think changes.

A schema is a mental representation of the world. Each ol us constructs schemas in our minds. We try to understand new things by applying our schemas to them. This process is called assimilation. For example, an infant has stacked blocks before. He has a "stacking schema." He then finds a new block. He can assimilate or fit this new object into his stacking schema. But what happens if the infant finds an open box? He finds that the stacking schema does not work. When he tries to stack, the block falls into the open box. Now the infant must adjust his schema to accommodate the new object.

Accommodation means adjusting one's schemas to include newly observed events and experiences. Together, accommodation and assimilation make intelligence grow. When new things do not fit existing schemas, we must create new schemas. This causes us to understand things in new ways. Infants' views of the world are limited to what they can see, touch, or taste. They cannot picture or think about things in their minds. When a young infant's toy is hidden, she acts as if it no longer exists. She does not look for it. But at 7 to 12 months, this changes. When the child sees you hide the toy under a blanket, she will look for it there. If you then hide it behind your back, the child will continue looking under the blanket. Later, at age 18 to 24 months, the child will have learned to look in the last place she saw you put it. She knows the toy must be somewhere. This is an important step in intellectual development.

The child understands that an object exists even when she cannot see or touch it. This is called object permanence. Achieving object permanence is evidence that the child can now picture (or represent) things in her mind. This is called representational thought.

Between the ages of 5 and 7, most children begin to achieve conservation. This means that they understand that the amount of something does not change when its appearance changes. For example, imagine you have two identical short, wide jars filled with water. You pour the contents of one jar into a tall, thin jar. A child under 5 will say that the tall jar contains more water than the short one. If you pour the water back into the short jar to show the amount has not changed, the child will still insist that the tall jar contained more water.

By age 7, however, the child will tell you that the tall jar contains the same amount of water as the short one. The principle of conservation is closely related to the idea of egocentrism. Young children are egocentric. This means that they cannot understand someone else's viewpoint.

Everyone goes through four stages of cognitive development in the same order but not necessarily at the same ages. In the sensorimotor stage, infants understand the world mostly through their body and senses. In the preoperational stage, they begin to use mental images or symbols to understand things. Children begin to use reason in the concrete operations stage, but have trouble with abstract ideas. In the formal operations stage the person is able to solve abstract problems.