Infants' ability to mentally track the orientation of an object during a hidden rotation was investigated (N = 28 in each experiment). A toy on a turntable was fully covered and then rotated 90°. When revealed, the toy had turned with the turntable (probable event), remained at its starting orientation (improbable event in Experiment 1), or…

Examined 5- to 12-year-olds' judgment regarding the behavior of balance scales and other levers whose arms varied in a causal or a noncausal variable. Results indicated age-related increases in correct judgments about the influence of physical features of objects at an earlier age than about spatial relations between objects. (MOK)