Although the Piagetian approach provided useful insights into cognitive evolution (see previous post), it ultimately proved to be limited in its applicability.
Why Piaget’s genetic epistemology was a useful tool:
- Piaget intended that the theory apply to all developmental sequences, and thus it was a general theory of development based on a study of children. Piaget himself even argued that it applied to the development of scientific theories themselves (recursion, anyone?). If the theory was truly general, it would apply in all circumstances, including the evolution of hominin cognition. When I applied his theory, I argued that I was applying a general theory of cognitive development to stone tools, not a model of children’s thinking. As you might imagine, no one paid attention to this assertion, and I was accused of comparing Homo erectus to modern eight-year olds, something I never actually did.
- Genetic epistemology identified and described styles of thinking that were less powerful than those used by modern adults. Several of these styles of thinking appeared to apply to non-human primates, and the Piagetian approach gained considerable traction among primatologists, beginning with Susan Parker and Kathleen Gibson’s classic 1979 article in Behavioral and Brain Sciences. Piaget’s stages could, in fact, be used as hypotheses for phylogenetic stages. I was able to point to specific characteristics of stone tools as reflecting abilities typical of specific stages of development. In other words, Piaget’s scheme could operate as an independent scale of cognitive development.
- As the most influential theory of cognitive development of the twentieth century, Piaget’s theory carried a lot of weight. Bringing it to bear on Palaeolithic remains provided me with a very powerful tool. Indeed, it was more like a bludgeon when talking to paleoanthropologists who had little or no background in psychology.
Some of the insights provided by genetic epistemology remain sound, especially the basic sequence in the development of spatial cognition. But eventually, I abandoned use of the theory, and it is perhaps instructive to examine why.
Why I abandoned the approach in the 1990s:
- My first inkling that all was not rosy came in a review of my work in the French journal l’Homme by Scott Atran. He commended my method, i.e., using an explicit cognitive theory to interpret stone tools, but condemned my choice of Piaget, referring to it as a ‘theoretical motley.’ I was a bit shocked, but shouldn’t have been. My strategy had always been to read Piaget as a primary source, and not refer to the secondary literature, including any criticism. When I looked seriously at the critical literature, I found that all was not well in Piagetian developmental psychology. Indeed, to put it frankly, Piaget was on the way out, for a number of reasons. Among others, it turned out that children did not all pass through his stages in the same order, let alone at the same time. Piaget himself knew this, but did not think it important. But it was. Interestingly, Atran’s review remains the single most intelligent and useful piece of criticism I have ever received.
- But more important for me was the fact that the theory did not ultimately work for human evolution, either. Even from the beginning I was troubled by some of the conclusions entailed by the theory. For example, the evidence from spatial cognition indicated adult level intelligence by probably half-a-million years ago. Very little about the 500,000-year-old archaeological record appears modern. I fell back on a kind of ‘unexpressed potential’ argument, with culture change accounting for all subsequent developments. But it was weak, and I knew it.
- Theories of general intelligence had fallen out fashion in favor of modular models of mental life (still strangely enshrined in popular literature, as when a failing student claims to have great emotional intelligence…). It did look as if many human cognitive abilities were not manifestations of a single general intelligence, but instead needed to be treated separately. Piaget’s theory did not match up well.
- The theory more or less ignored the brain. Of course, most psychological theories at the time did, too. But things were changing rapidly. First information processing theories set out to duplicate neural functioning, and none of these approaches could be reconciled with Piagetian development. In the 1980s and 1990s the brain sciences saw dramatic developments; science finally began to understand a little about how the brain worked, and Piagetian development again did not fare well.
- Finally, the Piagetian approach did not itself generate any further useful questions. I could sit back and defend my initial formulation, continue to tweak it through more precise chronologies, or look for a more defensible and productive theory. This sounds very clear and straight-forward in retrospect, but at the time it was not, and I floundered about a bit in the late 1980s before settling on cognitive neuroscience.