The ontogenesis of intelligence: Evaluating the Piaget theory

Abstract

T HE COMPLEXITY and the far-reaching implications of Jean Piaget’s theory of the ontogenesis of intelligence have been evaluated in a variety of ways by different investigators. Piaget’*3 has postulated 4 stages in normal intellectual development: sensorimotor (birth to 2 years); preoperational (2 to 7 years); concrete operational (7 to 11 years); and formal operational (above 1 I years). Crucial to an understanding of these 4 stages is Piaget’s concept of conservation (sameness, invariation) applied to matter and quantity. Conservation refers to the idea that the mass of an object remains the same no matter how much the form changes. Prior to the attainment of this concept, during the sensorimotor stage, the child’s thought is dominated by his perceptions. He cannot cancel out the effects of change in order to focus on elements of an experience which remain unchanged. During the preoperational stage, the child begins the development of language and recalls his repertoire of actions and responses to objects he encounters; it is “preoperational” because his thought processes are not yet reversible. He may be struck by similarities in the properties of objects, but he does not by his own actions arrange and disarrange them so that objects are ordered and related. During the third stage of concrete operations, reversibility of the thought process relating to a manipulation of an object is present, but the child’s thinking is still bound to direct experience. Piaget postulates that this reversibility of thought is essential before classification and seriation can occur. After entering the final stage of formal operations, the person can construct theories and make logical deductions without the necessity for direct experience. The experiments which Piaget utilized in deriving his theory of development of logical thought have been repeated by various investigators. The first replication study by Estes4 did not establish the stages postulated by Piaget. However, in general, later and more technically rigorous studies have supported his findings regarding the sequence of stages in terms of conservation of number and quantity.5-7 However most of the replication studies suggested that the stages are not as clearcut as proposed by Piaget and the development in a given child may be uneven (i.e., he may attain conservation in one task and not reveal it in another).8*g The replication studies have the common defect that each studies different groups of children over time to observe development. Goodnow studied Chinese school boys and found that there is gross similarity in performance on Piaget’s conservation tasks among boys of different nationality and education. Piaget also maintained that the attainment of the concept of conservation of