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…

The authors investigated the performance on simple multiplication and division problems of 8-year-old children longitudinally to determine the developmental trajectories of both operations. Twice a year, during 2 consecutive school years, children performed a multiplication and division verification task and a number-matching task. All effects…