Are Piagetian Scales Just Intelligence Tests?

Previous research has noted the relationships between Piagetian and Psychometric tests. The literature on this topic has revealed consistent and moderate-to-high magnitude associations and largely unidimensional tests. However, most of this literature has not explicitly assessed whether Psychometric general intelligence corresponds to a similar factor measurable with Piagetian tests. This study did just that by fitting structural equation models to available data from administrations of Piagetian and Psychometric tests given to the same samples. The tests were modeled separately, and then in models where they were featured together so their general factors could be correlated. The results of those analyses were then subjected to a meta-analysis (K = 8, N = 862) and the meta-analytic relationship between Piagetian and Psychometric general factors was found to be exceptionally high (r = .847). Piagetian scales thus test intelligence, and intelligence tests assess Piagetian development.