The Galileo bias: a naive conceptual belief that influences people's perceptions and performance in a ball-dropping task

This research introduces a new naive physics belief, the Galileo bias, whereby people ignore air resistance and falsely believe that all objects fall at the same rate. Survey results revealed that this bias is held by many and is surprisingly strongest for those with formal physics instruction. In 2 experiments, 98 participants dropped ball pairs varying in volume and/or mass from a height of 10 m, with the goal of both balls hitting the ground simultaneously. The majority of participants in both experiments adopted a single strategy consistent with the Galileo bias, showing no improvement across trials. Yet, for participants reporting intentions of dropping both balls at the same time, the differences between release points were significantly greater than 0 ms. These findings support separate but interacting cognition and perception-action systems.