Recent studies reveal that children can solve proportional reasoning problems presented with continuous amounts that enable intuitive strategies by around 6 years of age but have difficulties with problems presented with discrete units that tend to elicit explicit count-and-match strategies until at least 10 years of age. The current study tests…

In 4 studies, the authors examined how intuitions about the relative difficulties of the sciences develop. In Study 1, familiar everyday phenomena in physics, chemistry, biology, psychology, and economics were pretested in adults, so as to be equally difficult to explain. When participants in kindergarten, Grades 2, 4, 6, and 8, and college were…

In an attempt to devise a methodology for characterizing children's intuitive theories of drug action, 217 children in Grades 1 to 6 were interviewed about how two substances, alcohol and cocaine, cause behavioral changes in their users. Measures tapped both structure (Piagetian complexity of causal reasoning, coherence, and construction of a…