College students' performance on associated, corresponding tasks for horizontality

500 college biology students were asked to predict the axisymmetry (horizontal-vertical position) of the water surface and a swimming goldfish in a masked, sealed container. Subjects were shown the fish submerged in the semifilled container before it was slipped into a terry cloth stocking. The researcher then asked subjects to predict the position of the fish and the water surface as the sealed container was rotated to different angles. Many college students did not understand that liquids and submerged organisms remain invariantly horizontal regardless of the rotation of the container.