Wasn't Piaget a Pseudo-scientist like Freud? So why do we continue to spend so much of our class time teaching Piagetian Theory?

Piaget as a Scientifically-Rigorous Developmental Psychologist

Question

Wasn't Piaget a Pseudo-scientist just like Freud? He used poor methods, came to the wrong with an incorrect underlying perspective. It was just unscientific theorizing. So why do we continue to spend so much of our class time teaching Piagetian Theory? ~ (a composite summary of many e-mails to a teaching of psychology e-mail list)

Answer

I noticed the suggestion that Freud and Piaget are comparable in their lack of scientific rigor; in the last few years I noticed several list-members make similar claims about Piaget in other contexts. Four related concerns that I would like to challenge have been raised about Piaget: (1) poor methods, (2) wrong conclusions, (3) wrong underlying perspective, and (3) unscientific theorizing.

The biggest complaint about PIaget's methods is that he studied his three children (hardly a representative sample). In "Origins of Intellegence" every observation he reported to build his sub-stages of infancy was with his children. Our methodology standards (e.g., selecting samples) keep getting more rigorous; look at most classic studies and I believe you will find similar 'flaws' (e.g., early memory studies run on one-self). Despite flaws, most of Piaget's findings are still replicable today (if done the same way he did them). How many of us have so many replicable findings? Moreover, his findings from conservation tasks to magical thinking interviews were done with many other children. Though most of his books focus on giving many qualitative examples from many children, he also summarized data like we do today. For example, see page 121 of Inhelder & Piaget's "Early Growth of Logic in the Child" for a table of data summarizing when children understand class membership with 44 children in 3 age-groups on two versions of a task (yes, an experimental manipulation, to test a hypothesis!).

Some suggest Piaget came to the wrong conclusions. There are newer interpretations of many of his results; his object permanence findings are a focal point of debate. Diamond (from an information processing approach) suggests it's really memory and inhibition. Based on looking-time measures, Baillergeon (from a core knowledge approach) suggests younger infants have object permanence. Consider, though, how Piaget's object permanence results fit parsimoniously with the origins of separation anxiety. If Baillergeon is right, how come children do not experience separation anxiety by 5 months of age? Even if Piaget came to incorrect conclusions, that does not make his work any less scientific. Bohr was a brillant physicist even if his model of the atom was wrong; he did his best to explain all the evidence with the best concepts available to him. Piaget did the same.

Some question Piaget's underlying perspective: the individual child who actively constructs an understanding. We each bring our perspective to our research and it's hard to switch perspectives. I personally feel Piaget made some remarkably thought-provoking claims about distinguishing development from learning (e.g., when you master your multiplication tables, have you really "developed?"). But I also see the virtue in more precise theories even when they conflate our intuitions of learning and developing (e.g., Information Processing). Though Piaget clearly did not consider the social environment like Vygotsky did, the criticism of Piaget failing to consider the social environment seems over-blown. He thought about schools as a social context for development (see Piaget's "Science Education and the Psychology of the Child). Ironically, consider Gilligan's criticism of Piaget for interpreting boy's play as more likely than girl's play to lead to moral development. Can we name a Developmental Psychologist, alive or dead, who studied as many different domains (e.g., moral, number learning, folk biology) and considered them from as many perspectives (e.g., physical body, adaptation, internal motivation, peers, schools)?

Finally, Piaget is criticized for making an unscientific theory. Piaget made a falsifiable theory and he gathered evidence by observing children (not adult's providing retrospective accounts) in carefully set up situations (which he felt would best illuminate children's thinking, just like Baillergeon today feels looking-time measures get closer to infants' true thoughts). Piaget put together what he saw as the most parsimonious, simple, and complete explanation of development. He was keenly aware of scientific standards and sought to meet them. For example, he was very concerned that by proposing a stage theory, people might create unscientific teleological mechanisms to drive people through these stages (as though the final stage was the 'goal' of the others) rather than accounting for stages with scientific mechanistic causality. In case you're not 'in' to philosophy of science, here's an example of Pseudo- versus real science. Larmarkian Evolution and Intelligent Design use unscientific teleological mechanisms because they assume a future purpose that species change is directed towards whereas Darwin's Evolutionary Theory uses natural selection, a scientific mechanistic causality that explains species adaptations from only *prior* events. Piaget wrestled with how to answer the big questions of development and he never lost sight of doing that in a scientific way (see, for example, Piaget's "Insights and Illusions of Philosophy").

Piaget used impressive methods for his time. Like all developmental psychologists, he had a perspective, yet his was relatively broad. Whatever his flaws, Piaget was dedicated to the scientific explanation of development, and I do not feel it is appropriate to equate him with pseudo-science.