“…Brown & Desforges (1977) argue that stages by definition involve a 'coherent integration of operations' and that, when this can be shown not to be the case, the utility of the concept breaks down. If low correlations are observed between tasks intended to demonstrate the same sort of intellectual functioning, the concept of a stage is seriously at risk (Pascual-Leone, 1970;Blasi & Hoeffel, 1974;Hamel, 1974;Neimark, 1975;Schwebel, 1975). More radically, if children between 5 and 7 years of age show an ability to make inferences that belong to the formal operational stage, there are serious consequences for major Piagetian claims (Harris, 1975).…”