Piaget placed great emphasis on the child’s ability actively to make sense of the world. Children do not passively soak up information, but select and interpret what they see, hear and feel in the world around them. From his observations of children and the numerous experiments he conducted on their ways of thinking, he concluded that human beings go through several distinct stages of cognitive development – that is, learning to think about themselves and their environment. Each stage involves the acquisition of new skills and depends on the successful completion of the preceding one.

    The first stage is the sensorimotor, which lasts from birth up to about age two. Until aged about four months, an infant cannot differentiate itself from the environment. For example. The child does not realize that its own movements cause the sides of its cot to rattle. Objects are not differentiated from persons, and the infant is unaware that anything exists outside the range of its vision. As research we have already looked at shows, infants gradually learn to distinguish people from objects, coming to see that both have an existence independent of their immediate perceptions. Piaget calls this early stage sensorimotor because infants learn mainly by touching objects, manipulating them and physically exploring their environment. The main accomplishment of this stage is that by its close the child understands its environment to have distinctive and stable properties.

    The next phase, called the pre-operational stage, is the one to which Piaget devoted the bulk of his research. This stage lasts from age two to age seven, when children acquire a mastery of language and become able to use words to represent objects and images in a symbolic fashion. A four-year-old might use a sweeping hand, for example, to represent the concept ‘aeroplane’. Piaget terms the stage pre-operational because children are not yet able to use their developing mental capabilities systematically. Children in this stage are egocentric. As Piaget uses it, this concept does not refer to selfishness, but to the tendency of the child to interpret the world exclusively in terms of its own position. She or he does not understand, for instance, that others see objects from a different perspective from her or his own. Holding a book upright, the child may ask a picture in it, not realizing that the person sitting opposite can only see the back of the book.

    Children at the pre-operational stage are not able to hold connected conversations with someone else. In egocentric speech, what each child says is more or less unrelated to what the previous speakers said. Children talk together, but not to one another in the same sense as adults. During this phase of development, children have no general understanding of categories of thought that adults tend to take for granted: concepts such as causality, speed, weight or number. Even if the child sees water poured from a tall, thin container into a shorter, wider one, he or she will not understand that the volume of water remains the same – concluding that there is less water, because the water level is lower.

    A third stage, the concrete operational period, lasts from ages seven to eleven. During this phase, children master abstract, logical notions. They are able to handle ideas such as causality without much difficulty. A child at this stage of development will recognize the false reasoning involved in the idea that the wide container holds less water than the thin, narrow one, even though the water levels are different. She or he becomes capable of carrying out the mathematical operations of multiplying, dividing and subtracting. Children by this stage are much less egocentric. In the pre-operational stage, if a girl is asked ‘How many sisters have you?’, she may correctly answer ‘one’. But if asked, ‘How many sisters does your sister have?’ she will probably answer ‘nont’, because she cannot see herself from the point of view of her sister. In the concrete operational stage the child is able to answer such a question correctly with ease.

    The years from eleven to fifteen cover what Piaget calls the formal operational period. During adolescence, the developing child becomes able to grasp highly abstract and hypothetical ideas. When faced with a problem, children at this stage are able to review all the possible ways of solving it and go through them theoretically in order to reach a solution. The young person at the formal operational stage is able to understand why some sorts of questions are trick ones. To the question ‘What creature are both poodles and dogs?’/ the child might or might not be able to give the correct reply (the answer is ‘poodles’), but he or she will understand why this answer is right and appreciate the humour in it.

    According to Piaget, the first three stages of development are universal; but not all adults reach the formal operational stage. The development of formal operational thought depends in part on processes of schooling. Adults of limited educational attainment tend to continue to think in more concrete terms and retain large traces of egocentrism. 

Criticisms

    Margaret Donaldson has questioned Piaget’s view that children are highly egocentric, compared to adults. The tasks which Piaget set the children he studied, as she sees it, were presented from an adult standpoint, rather than in terms that were understandable to them. Egosentrism is equally characteristic of adult behaviour - –n some situations. To make the point, she quotes a passage from the autobiography of the British poet Laurie Lee, describing his first day at school as small boy.

    “I spent that first day picking holes in paper, then went home in a smouldering temper.

    ‘What’s the matter, Love? Didn’t he like it at school then?’

    ‘They never gave me a present.’

    ‘Present? What present?’

    ‘They said they’d give me a present’.

    ‘Well now, I’m sure they didn’t.’

    ‘They did! They said, “You’re Laurie Lee, aren’t you? Well; just sit there for the present. “I sat there all day but I never got it. I ain’t going back there again’.

    As adults we tend to think that the child has misunderstood, in a comic way, the instructions of the teacher. Yet on a deeper level, Donaldson points out, the adult has failed to understand the child, not recognizing the ambiguity in the phrase ‘sit there for the present’. The adult, not the boy, is guilty of egocentrism.

    Piaget’s wark has also been much criticized on grounds of his methods. How can we generalize from findings based on observations of small numbers of children all living in one city? Yet for the most part Piaget’s ideas have stood up well in the light of the enormous amount of subsequent research they have helped to generate. The stages of development he identifies are probably less clear-cut than he claimed, but many of his ideas are now generally accepted.