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Lesson 8: Cognitive Development: Piaget and Information Processing

Lesson Overview

In this lesson we will examine the development of thought, including such skills as remembering, problem solving, classifying, and imagining. We will compare Piaget's stage theory of cognitive development to information-processing theories and discuss the merits and shortcomings of each.

Lesson Objectives

After completing this lesson, you will be able to

* identify the differences between Piaget's theory and information-processing theories of cognitive development;

* define the characteristics of a stage theory and explain how it differs from a theory of quantitative development; and

* understand the several main areas of focus in the study of child development, particularly classification, memory development, and problem solving.

Reading Assignment

Read through the study notes first; then read chapters 9 and 12 (pages
444-66 only) in your textbook.

Key Terms


stage theory



concrete operations

formal operations


information processing


short-term memory

long-term memory

domain-specific knowledge



Study Notes

The term cognition refers to the inner processes and products of the human mind that lead to knowing. Thus, cognition covers such disparate skills as thinking, remembering, relating, classifying, symbolizing, imagining, problem solving, fantasizing, and dreaming. In this lesson we will examine two different approaches to understanding the development of cognition: Piaget's stage theory and information processing.

Piaget's Theory

Jean Piaget, a Swiss psychologist, developed the most comprehensive and well-known theory of child development by observing and documenting the behavior of his own and other children. Piaget was interested in how children develop the capacities to think, reason, understand, and remember. His theory is a stage theory; he proposed that children go through qualitatively different stages as they develop into mature adult thinkers. This is an important point in comparison to most other theories of cognitive development (such as information processing), which emphasize quantitative differences between children's thinking and adult cognition.

Piaget proposed that the function of intelligence is that it allows humans to adapt to different situations.

Although Piaget's theory is fairly complex, there are only a few principles that you will need to remember in order to understand how he viewed cognitive development.

Function, Structure, Content

Piaget divided intelligence into three main parts: function, structure, and content. Piaget proposed that the function of intelligence is that it allows humans to adapt to different situations. This adaptation occurs in two ways: assimilation and accommodation (these will be discussed below). The structure aspect refers to an organization of cognitive structures. It is this aspect of Piaget's theory that makes it "constructivist." These structures begin with the earliest basic reflexes, and they change (through adaptation) and become reorganized over the course of development. The structures in this theory are similar to a grammar for language: They contain the rules for working on information. Finally, the content of intelligence refers to the actual pieces of information and specific knowledge involved. To continue the language metaphor, the content would refer to the words of a language. Piaget proposed that the cognitive structures he described were content-free (which becomes very important when we talk about criticisms of this theory).

Stage Theory

Piaget's theory is one of the best known stage theories in child development (Freud's theory is another). A stage theory is distinguished by the fact that each stage occurs in an invariant order. Because each stage builds on the advances of the previous stage, it is impossible to skip a stage or pass through them in any other order. Although we tend to think of stages in terms of the age during which a child passes through them, Piaget warned against relying too heavily on age norms. It is plausible that a child may, for example, show evidence of concrete operational thought before the age of seven; the important thing to remember is that the order is invariant. For ease of understanding, I will mention the normative ages for each stage, but keep in mind that these shouldn't be seen as restrictions.

Piaget's Stages

The four stages of cognitive development in Piaget's theory are as follows:

* Sensorimotor (approximately birth to two years old)

* Preoperational (approximately two to seven years old)

* Concrete operational (approximately seven to eleven years old)

* Formal operational (approximately eleven to fifteen years old to adulthood)

The hallmark achievement of this first stage is the development of mental representation.

During the sensorimotor stage of cognitive development the infant develops from having only basic reflexes and little capacity for understanding the world to a creature who can mentally represent ideas and objects. Piaget focused on several tasks that illustrate this development. The most famous is the A-not-B task, which illustrates the achievement of object permanence (for a reminder about this work, review lesson 3). Another achievement of the sensorimotor period is intentional (or goal-oriented) behavior. At the beginning, infants' actions are not intentional; during the sensorimotor stage, infants begin to do things intentionally, like imitating other people and playing games. The hallmark achievement of this first stage is the development of mental representation. Mental representation refers to the ability to make one thing stand for something else. Representation is apparent in infancy when the child will do deferred imitation (for example, imitating a tantrum one evening that he saw another child throw in the afternoon) and make-believe play (such as pretending a banana is a phone).

Operations refers to the ability to mentally act on information.

Once the child has attained the ability of mental representation, she passes into the preoperational stage. As its name suggests, the stage of preoperations is defined more by what abilities the child doesn't have, rather than what she does have. The term operations refers to the ability to mentally act on, or transform, information. Without this ability, children have very limited understanding of the world. For example, this stage is characterized by egocentricity, or the inability to take the viewpoint of another (see Piaget's three-mountain task on page 319). Some of you may have experienced another form of egocentricity if you have ever talked with a preschooler on the phone and the child points to something she wants you to "see." Most importantly for this stage, preoperational children fail Piaget's conservation tasks. The conservation tasks are explained in greater detail in your textbook, but the main points are that preoperational children fail because they tend to focus on states rather than transitions, they become centered on one characteristic of the display, and they focus on the outward appearance of the display.

The next stage, called concrete operations, is when the child can do mental transformations and pass the conservation tasks. One important point about operations in general is that they exhibit reversibility. This means understanding that if water is poured from a tall, thin glass to a short, fat glass (so the level of water will change), when the water is poured back into the tall, thin glass, it will rise to the same level as it was at first. This stage is called concrete operations because children can only do mental operations on concrete, tangible information they can perceive. Children at this stage cannot do operations on abstract ideas.

The ability to do operations on operations, abstract thinking, and metacognition is the mark of formal operations, the last stage of cognitive development. During this stage, children can do hypothetical deductive reasoning (or test theories in order to solve problems), and thought is propositional (children can think about verbal assertions and abstract ideas).

Information-Processing Theories

Until about fifteen years ago, Piaget's theory was the only one to attempt to fully explain cognitive development, and even today it remains the most comprehensive. But certain aspects of the constructivist account have been questioned in recent years, and alternative accounts have been offered. Many of these theories are gathered under the heading of information processing.

Information-processing approaches share a model of cognition that looks like this:

/-----------------Executive Control------------------------------------\

Env'tal Input --> Sensory Store --> Short-Term Memory --> Long-Term Memory

The figure shows how information goes from the environment into short-term (or working) memory, and then into long-term memory. The sensory store refers to taking in information through our senses. If attention is paid to that information, it goes into short-term memory, where a small amount of information can be held for less than thirty seconds, unless it is rehearsed. Any information that is operated on in short-term memory will then pass into long-term memory, which is a permanent storehouse of information and operating strategies. Keep in mind that these words are only metaphors; there is no area in the brain that could be identified as the "short-term memory" lobe. Finally, executive control is where we regulate our attention, select strategies for solving problems, and monitor what we are thinking about.

Information-processing approaches are quantitative, whereas Piaget's theory is qualitative.

Information-processing approaches are quantitative, whereas Piaget's theory is qualitative. In other words, information-processing approaches argue that children's thought processes change quantitatively over childhood--what changes is how much information they have and how it is organized. These theories do posit some changes in a few basic cognitive skills, such as memory and attention, but again, these changes are quantitative; the skill is the same throughout the life span, but there is an increase in the amount of information that can be handled.

Piaget thought that children fail to solve certain problems and appear to think differently from adults because they lack important cognitive structures. How would information processing explain the results that Piaget found? We will look at the development of the cognitive processing skill of attention as an example of an alternative explanation for why children fail at some of Piaget's tasks.

Development of Attention

The ability to pay attention develops gradually over childhood, and it is important to understand this when testing children of different ages. Infants have a very short attention span; they will often pay attention to a display for only a matter of seconds before looking away. In the preschool years children can do a task for a few minutes before being distracted, even when the task is something they enjoy, like watching TV. You may remember on cartoons and children's shows that when they break for a commercial, they say, "After these messages, we'll be right back." This is because preschool children cannot pay attention for long periods of time, and they are likely to wander off during the commercial break.

The short attention span of children from birth to age five is an alternative explanation for some failures in Piaget's cognitive tasks. Consider the conservation tasks: It is possible that preschoolers fail these tasks simply because they do not pay attention long enough to gather all the relevant information.

By the age of five, children are much more persistent in trying to solve problems, but their strategies are unsystematic. By the age of eight, children are much more systematic, but they sometimes show a lack of planning. These skills related to attention may have an effect on how children perform on problem-solving tasks such as the conservation tasks.

One of the purposes of attention is to filter out unwanted information. Right now you are trying to read a lesson on attention, but you can also feel the chair you are sitting on, maybe see out of a window, and think about what you need to buy at the grocery store. In order to successfully learn this lesson, though, you must try to "tune out" this other information and pay attention to what is relevant at the moment.

The ability to use attention as a filter develops over childhood.

The ability to use attention as a filter also develops over childhood, and may seriously affect children's performance on cognitive tasks. Young children tend to take in everything around them, even when you teach them what to pay attention to. In one study, seven- and thirteen-year-old children were told to remember the number and location of pictures of animals under different flaps. Under some of the flaps were household objects. The thirteen-year-olds did much better than the seven-year-olds at remembering where the animals were. But when the researchers tested for memory of where the household objects were, the seven-year-olds did better than the older children. This is called "incidental learning" because the younger children picked up information they didn't need to. The older children were much better at attending to only the relevant information and filtering out the information they didn't need.

As adults we have strategies for paying attention to things. If we were in the study just mentioned, we would probably only look at the animal cards; we might try to find a pattern to remember where they were, and we might even repeat their locations to ourselves. What do children know about their ability to pay attention? When the researchers asked the children in the study what they should do to remember the information in the task, even the seven-year-olds said that they should look at the animals first and label them in order to remember them. However, even though they knew this strategy, they didn't perform very well. The same effect is found in memory, where children know some strategies for remembering earlier than they can successfully use them.

Memory is another example of a cognitive skill that is studied in information-processing terms. Following the example of attention, it is easy to see how differences in the amount of information that can be remembered would affect performance on many (if not all) of Piaget's tasks. In addition to focusing on quantitative changes in cognition, information-processing approaches have found differences in what is called "domain-specific knowledge." Remember that Piaget claimed that mental structures were content-free, in other words, any information can be fed into the mental structures and worked on in the same way. However, recent studies have shown that children can often do better on tasks that are familiar to them. For example, when given lists of dinosaurs to remember, and facts about them, eight-year-olds will sometimes perform better than college students. For other types of information (like a grocery list) an eight-year-old cannot remember as well as a college student. When the information is relevant, or interesting to them, children perform better. This too may have had an effect in Piaget's tasks.

Study Questions

1. A five-year-old is given the conservation of liquid test. He fails to conserve, in that he says when the water is poured into the short, fat glass that there is now less water than there was in the tall, thin glass. What is Piaget's specific explanation for this failure? (In other words, what is the child doing wrong?) What would an information-processing theory suggest might be the child's problem?

2. Think about how to test the information-processing explanation you came up with for question 1. What additional questions would you ask the child? How would you change the task to show that the alternative explanation for the child's failure is more accurate?

3. Write a script (as explained in the textbook) for eating in a restaurant from (a) a preschooler's point of view and (b) a college student's point of view. How do the scripts differ?

4. How does studying the development of play throughout childhood give us insight into cognitive development? Give three specific examples of how play develops and how it is related to cognition.

5. Your textbook describes preschool cognition as uneven; what does that mean? Why is this unevenness a problem for some theories of development (be specific)?

Written Assignment

Write a two- to three-page (typed, double-spaced) essay on one of the following topics. Your essay needs an introduction to the problem, a body that discusses the issues in a clear manner, and a conclusion that sums up what you have discussed. You can gather the relevant information from your textbook (you may want to read ahead) and study guide. Be sure to address all parts of the question you choose. The essay is due before you begin
lesson 9.

1. Discuss the mother-infant attachment relationship. What are the differences between securely and insecurely attached children? What factors lead to different attachment relationships? Why is attachment important for development? Can a child's attachment with another person change over time? What are the differences between the mother-infant and the father-infant attachment relationships?


2. Using an example from each stage of development, show how differences in children's play in infancy, the preschool period, and middle childhood are related to advances in cognitive ability. Give specific examples of types of play and specific cognitive skills. What cognitive changes allow the child to play differently in preschool from the way she did as an infant? What cognitive advances in the development to middle childhood affect children's play patterns? What do children learn from playing during each of these stages?

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