Judgments of natural and anomalous trajectories in the presence and absence of motion.

Recent studies have shown that many people demonstrate erroneous beliefs about motion when asked to predict the trajectories of objects. The present experiments examine whether people can select as correct natural trajectories over anomalous ones when presented with the actual on-going event (motion condition) or static representations of the event (no-motion condition). McCloskey's curved tube problem was used as the event. Results indicate that adults benefit from the motion information in these stimuli, choosing the correct path more often in the motion condition. Men performed better than women in both conditions; this gender effect could not be attributed to formal instruction in physics. Only in the no-motion condition did any men prefer a path which reflected an impetus model of motion. Some women chose a curvilinear path in the motion condition, and in the no-motion condition the curvilinear path was their most often selected alternative. Fifth-grade children demonstrated no effect for gender and their path preferences resembled those of adult males. Children's responses failed to demonstrate a preference for those curvilinear paths which reflect an impetus-based approach to the problem. Adults' performance in the no-motion condition was not enhanced by instructions to employ mental imagery of the event.