Psychology – Videos (Piaget)



Evaluation of Piaget’s Theory


  • The influence of Piaget’s ideas in developmental psychology has been enormous. He changed how people viewed the child’s world and their methods of studying children. He was an inspiration to many who came after and took up his ideas. Piaget’s ideas have generated a huge amount of research which has increased our understanding of cognitive development.
  • His ideas have been of practical use in understanding and communicating with children, particularly in the field of education (re: Discovery Learning).


  • Are the stages real? Vygotskyand Bruner would rather not talk about stages at all, preferring to see development as continuous. Others have queried the age ranges of the stages. Some studies have shown that progress to the formal operational stage is not guaranteed. For example, Keating (1979) reported that 40-60% of college students fail at formal operation tasks, and Dasen (1994) states that only one-third of adults ever reach the formal operational stage.
  • Because Piaget concentrated on the universal stages of cognitive development and biological maturation, he failed to consider the effect that the social setting and culture may have on cognitive development (re: Vygotsky, 1978).
  • Piaget’s methods (observation and clinical interviews) are more open to biased interpretation than other methods. Because Piaget conducted the observations alone the data collected are based on his own subjective interpretation of events. It would have been more reliable if Piaget conducted the observations with another researcher and compared the results afterwards to check if they are similar (i.e. have inter rater reliability).
  • As several studies have shown Piaget underestimated the abilities of children because his tests were sometimes confusing or difficult to understand (e.g. Hughes, 1975).
  • The concept of schema is incompatible with the theories of Bruner (1966) and Vygotsky (1978). Behaviorism would also refute Piaget’s schema theory because is cannot be directly observed as it is an internal process. Therefore, they would claim it cannot be objectively measured.
  • Piaget carried out his studies with a handful of participants (i.e. small sample size) – and in the early studies he generally used his own children (from Switzerland). This sample is biased, and accordingly the results of these studies cannot be generalized to children from different cultures.