Jean Piaget

1896-1980
French psychologist, philosopher, and naturalist.

Jean Piaget is universally known for his studies of the development of intelligence in children. Although he is one of the creators of child psychology as it exists today, psychology was for him only a tool of epistemology (the theory of knowledge). He identified his domain as "genetic [i.e., developmental] epistemology." He thus studied the growth of children's capacity to think in abstract, logical terms, and of such categories as time, space, number, causality, and permanency, describing an invariable sequence of stages from birth through adolescence. A prolific author, he wrote over fifty books and hundreds of articles.

Jean Piaget (Farrell Grehan/Corbis. Reproduced with permission.)

Piaget was born in 1896 in the French-speaking Swiss city of Neuchâtel, the son of an agnostic medievalist and a religious mother with socialist leanings. After completing a doctoral thesis in natural sciences (1918), and studies in psychology and philosophy in Zurich and Paris, he joined the Rousseau Institute of Geneva in 1921, which was founded by Edouard Claparède as a center for research on child development and education. He later taught experimental and developmental psychology, sociology, and history and philosophy of sciences, mainly at the University of Geneva. Piaget died in 1980. His interdisciplinary International Center for Genetic Epistemology (established in 1955) closed in 1984.

As an adolescent, Piaget published numerous papers on the classification of mollusks. During World War I, he was active in socialist and Christian student groups, and sketched a theory of organic, psychological, and social phenomena aimed at providing a scientific basis for postwar reconstruction. Much of his later thinking built directly on his youthful speculations and values, but its empirical impetus derived from his own reaction against the metaphysical and mystical tendencies of his adolescence.

Piaget devised a "clinical method" that combined standard intelligence tests and open-ended conversations with school-age children. In his first five books, he studied children's language, reasoning, conceptions of the world, theories of causality, and moral judgment. He found that children are at first "egocentric" (incapable of taking another person's point of view) and attached to concrete appearances, but that they gradually move away from egocentrism and become capable of abstract thinking. Piaget's observations of his own children led to The Origins of Intelligence (1952) and The Construction of Reality (1954), where he describes how basic forms of intentionality, and of the categories of object, space, causality, and time evolve between the onset of the newborn's reflex activities and the emergence of language at about 18 months; Play, Dreams, and Imitation (1951), deals with the development of mental representation up to the age of six. In these three classics, Piaget expounded the notion of intelligence as a form of adaptation to the external world. Starting in the 1940s, Piaget and Bärbel Inhelder studied the development of logical and formal thought in various fields (conceptions of movement, speed, time, space, geometry, chance, and probability). One of his major works, Introduction to Genetic Epistemology (1950), remains untranslated.

Piaget and his collaborators created many original and ingenious problem-solving situations that became paradigms for research all of the world. In one famous experiment, children sat facing a scale model of three mountains and were asked to choose from a series of pictures the one that represents the mountains as seen by a doll sitting at other positions. Younger subjects systematically identified the doll's viewpoint with their own. Studies of "conservation" provide further notable examples: the child is presented with two identical balls of clay; the shape of one is modified, and the child is asked whether the amount, weight, or volume of clay has changed. Other situations involve manipulating blocks or pouring identical quantities of liquid in differently shaped containers.

Most of the research Piaget inspired is disconnected from the theoretical goals of genetic epistemology. His work had some direct impact on mathematical and moral education, and reinforced the belief that instruction must be adapted to the child's developmental level. But it is Piaget's investigative techniques, formulation of new problems, insightful observations, and emphasis on the development of cognitive capacities that form some of the bases of contemporary child psychology.