We studied developmental trends in 5 important reasoning tasks that are critical components of the operational definition of rational thinking. The tasks measured denominator neglect, belief bias, base rate sensitivity, resistance to framing, and the tendency toward otherside thinking. In addition to age, we examined 2 other individual difference…

When children learn to count and acquire a symbolic system for representing numbers, they map these symbols onto a preexisting system involving approximate nonsymbolic representations of quantity. Little is known about this mapping process, how it develops, and its role in the performance of formal mathematics. Using a novel task to assess…

In the literature, learners' cognitive development is mainly discussed with respect to changes in learners' content-dependent knowledge (conceptual change or growth). Additional dimensions of time and complexity may also be taken into account to describe cognitive processes in at least three dimensions. We discuss these three dimensions of…