Jean Piaget has been perhaps the most influential developmental psychologist of the twentieth century. His studies of the growth of intelligence in Swiss school children became the basis of a general theory of intelligence that has since been applied in the fields of psychology, education, anthropology, and primatology, to name just a few. While his theory was based on studies of children, it was always Piaget’s intention that the theory be applicable to all sequences of development; human children simply provided the most complete and observable sequence.
The theory is a stage theory. Human children pass through a sequence of stages that is invariant. The rate at which they pass through the stages varies from individual to individual, but the sequence itself is necessary; no stage can be skipped, because it is a prerequisite for the succeeding stage. The theory is also a structural theory. It conceives of intelligence as a set of principles used to organize behavior, principles that are ultimately patterns of brain activity. But these principles are not learned in a simple behaviorist sense.Rather, simple genetically determined structures are elaborated during maturation into more and more sophisticated kinds of organization (Wynn 1985). It is the action of the individual in his environment that leads to this elaboration.
In other words, the individual does not passively receive new principles but must construct them himself (Piaget 1970). Mr. Piaget’s developmental scheme consists of four major stages: sensorimotor, pre-operations, concrete operations, and propositional operations. Sensorimotor is the intelligence of action.The way a new born infant would grasp something would be a prime example.
Not long after birth, the infant will be able to turn the simple task of gripping into gripping and tugging, perhaps for examination or maybe to suck on. Sensorimotor intelligence lacks any actual thought though. That leads me to my next stage, preoperational intelligence. The internal representation of action that is characteristic of preoperational thinking results from the semiotic ability that is a prerequisite for language and this ability to ‘think’ an action gives the preoperational stage some important capabilities.One is the ability to project action into the future and to contemplate the past action (Wynn 1985). Preoperational thinking is limited only to the sequence of actions, one after another. In short, preoperational thinking is only able to consider one variable at a time.
A famous example from Piaget’s work illustrates this limitation. When clay balls were rolled into sausages, a preoperational child assumed that the amount of clay had increased because the length had increased. She was unable to consider length and thickness simultaneously (Wynn 1985).Operation intelligence is achieved by adults. Unlike the previous two, we are now able to consider an action and it’s opposite simultaneously. In addition, we are also able to consider multiple variables as opposed to just one.
Operational thought consists of two stages, concrete and propositional operations. Both have the same organizational principles, but differ in the realms of application (Wynn 1985). Concrete operations organizes people or things, basically any noun. Propositional, on the other hand, organizes hypothetical entities.
A math problem would be a great example of propositional operations. The Piagetian scheme is of course far more detailed than I’ve previously stated. It has been described for many different kinds of behavior, from math to moral development, and each of the major stages has been divided into sub stages. Most of these are too subtle to be reliably applied in prehistory, however, and we must be content with the coarser scheme (Wynn 1985). Piagetian theory fulfills the basic requirements of a workable theory of intelligence that were discussed above. It is clearly evolutionary in its intent.Piaget intended that the theory be generally applicable to all sequences of development and even acknowledged that the ideal subject of study would be the psychology of fossil humans (Piaget 1970).
As a result, his definition of intelligence is a general one that is not specifically designed to evaluate humans. Organizational ability is a concept that can be used to discuss the behavior of amoebas as well as the behavior of human adults. While it would be overly optimistic to conclude from these results that Piaget’s developmental scheme is universally true in detail, it appears thatPiaget has described the rough outline of a sequence of real categories of intelligence (Wynn 1985). In sum, I have chosen Piaget’s theory for many reasons. His work dates back to the earliest Neanderthals. Mr. Piaget paved the way for everyone else seeking more information on not just the evolution of intelligence but the evolution of humans as well and it broadened the knowledge tremendously of anyone who read or studied his work.
References Wynn, T. World Archaeology, Vol. 17, No. 1, Studying Stones (Jun. , 1985), pp.
32-43 Piaget, J. Genetic Epistemology. (Trans. E. Duckworth) 1970.
New York: Viking.