This lecture is a primer on the emergence of thinking and understanding. I will do this by briefly discussing three influential perspectives on cognitive development. I will start with the theory of the Swiss psychologist Jean Piaget, arguably the most influential theory on cognitive development. This theory describes cognitive development in four clear stages and therefore offers a good starting point.
Next I will focus on the sociocultural theory proposed by the Soviet Psychologist Lev Vygotsky. The major contributions of this theory are its focus on social and cultural influences on cognitive development, and the importance of language.
Finally, I will briefly explain the information processing approach. This approach offers the most precise descriptions of the development of various cognitive skills. It also clearly links cognitive development to developments in the brain I previously discussed, and can take into account various influences from the environment.
Let’s start with Piaget. He proposed that children continually seek to understand the world around them and explore the possibilities it offers. As the brain matures, and the abilities to perceive and act grow, children’s experiences get increasingly rich and varied, offering much knowledge.
According to Piaget, children organize this knowledge in cognitive schema’s. Such schema’s help us quickly understand the world, know what to expect and how to react. For instance, if a child encounters an animal with a tail, 4 legs, and with someone on its back, his horse schema may help identify the animal. Similarly your public transport schema tells you where and for what kind of signs to look when you need to find a subway entrance.
Such schema’s are the building blocks of intelligent behavior. During development children will try to assimilate experiences with new objects or situations by applying current schema’s. However, when these schema’s fall short they accommodate the new information by updating the schema or making a new one. For instance when a “humped-horse”, turns out to be a camel.
According to Piaget cognitive development reflects a progressive reorganization of ever more elaborate schema’s, during 4 four universal stages of development.
During the first 2 years of life children are in the sensorimotor stage, in which they explore the world through the perceptions of their senses and motor actions. By the end of this stage children have learned to form mental representations of objects, persons and actions. This is the foundation upon which many cognitive abilities rest.
Next is the preoperational stage, which spans the years between 2 to 7. Over this period the ability to use symbols or internal images to represent objects, persons and events that are not present increases dramatically. This is seen in pretend play, drawing and speaking. But the representations tend to be egocentric and focus on a single dimension of an event or problem.
During the concrete operational stage, extending from 7 to about 11 years, thought becomes much more logical, flexible, organized and resembling the reasoning of adults. Children have now acquired the ability to use and integrate multiple dimensions to interpret a situation or solve a problem. However, logical thinking is still limited to concrete information that is directly perceived.
Finally, around the age of 11 children enter the formal operational stage, in which they develop the capacity for abstract, systematic and scientific thinking. Their logical reasoning is no longer limited to concrete things or events, but also includes the abstract and hypothetical. Now children are able to come up with general logical rules.
As you will find out later during this course, this theory has many strengths but also limitations, one of which is the relative lack of attention for social and cultural influences on cognitive development. This is exactly what was emphasized most strongly in Vygotsky’s sociocultural theory.
Vygotsky believed that children develop by doing tasks that are too difficult for the child alone but can be achieved with help from an adult or more skilled peer. Such tasks are in what he called, the child’s zone of proximal development. Thus, he envisioned development as a social process requiring sufficient scaffolding by others. Indeed, there is much evidence to support the social origins of cognitive development.
Another difference with Piagets theory is that Vygotsky regarded language as the foundation for all higher cognitive processes, like controlled attention, abstract reasoning, self-reflection and so on. You can hear young children use self-directed speech to guide themselves during difficult tasks. As children grow older this private speech grows softer and gradually internalizes completely. (Although I must admit that I still talk to myself from time to time, and won’t speculate on what that might say about my cognitive development.)
Vygotsky’s theory helps us understands the wide cultural variation in cognitive development because social interactions are inherently influenced by what is valued in a particular culture.
A limitation of both theories is that they are rather vague on how cognitive skills develop. This is precisely the focus of the information processing perspective.
This approach views the mind as an information processor, somewhat similar to a computer. Cognitive performance hinges on two factors: the hardware, like memory capacity and processing speed, and the software, the strategies and information that are available. Cognitive development then, entails a continuous upgrading of both the hardware and software, allowing children to solve ever more complex problems.
Take for instance memory, which is central to everything we do. Usually three types of memory are distinguished: Sensory memory, working memory and long term memory.
Sights sounds and other sensations we perceive are very shortly stored in raw form in sensory memory. It can then be transferred to working memory or is lost. Long term memory on the other hand stores information enduringly. Working memory is the place where we can “work” with information from sensory memory and long term memory. For instance when a child hears the teacher dictate B–I-R-D, the sounds enter sensory memory. In working memory, these individual sounds can be integrated with information from long-term memory, to produce the word BIRD along with its meaning.
Development in each of these three subsystems is quite different. The capacity of sensory memory increases only a little over development, while the capacity and efficiency of working memory increases dramatically. For long term memory it is not so much the capacity that changes, which is thought to be virtually unlimited, but the ease with which things can be stored and retrieved increases.
These changes partly result from brain development. Myelination allows signals to travel faster through neurons, and synaptic pruning leads to increasingly more efficient networks of connections between neurons. These factors increase processing speed and thereby give room for more and more complex cognitive operations.
Cognitive development also reflects use of increasingly more efficient strategies for information processing. For instance, children may learn that rehearsal improves retention, and learn to focus only on information that is relevant for the task at hand. In addition, the increasing body of knowledge makes it ever more easy to fit new information in existing knowledge structures in long term memory, and to use cues for retrieving it. Also children become more and more skilled and flexible in applying the most efficient strategy. It is clear that these developments are heavily influenced by external factors that stimulate specific uses of knowledge and strategies, for instance by instruction.
Unfortunately environmental influences can also impair cognitive development. For instance, it is found that growing up under difficult circumstances affects the development of brain structures involved in working memory, which in turn to affect working memory performance.
The strength of the information processing approach is that it provides detailed information about the development of many aspects of cognition, of which memory is just one example, and shows clearly how these developments are related to biological and various environmental factors.
In this lecture I have illustrated cognitive development very broadly using the theory of Piaget, and the four stages of development he proposed. I also emphasized the importance of social interactions and thereby cultural influences on cognitive development, as illustrated by the sociocultural theory of Vygotsky. Finally I showed how development can be described in more detail for separate aspects of cognition by focusing on the information processing perspective.
This is just the smallest tip of the iceberg of knowledge and views available on cognitive development. I will address more issues regarding various influences on development in the next lecture, but I also encourage you to use the developmental systems perspective to find out more about cognitive development yourself.
