Pushing people to their tipping point: Phenomenal tipping point is predicted by phenomenal vertical and intuitive beliefs

Previous work has shown that people overestimate their own body tilt by a factor of about 1.5, the same factor by which people overestimate geographical and man-made slopes. In Experiment 1 we investigated whether people can accurately identify their own and others' tipping points (TPs) - the point at which they are tilted backward and would no longer be able to return to upright - as well as their own and others' center of mass (COM) - the relative position of which is used to determine actual TP. We found that people overestimate their own and others' TP when tilted backward, estimate their own and others' COM higher than actual, and that COM estimation is unrelated to TP. In Experiment 2, we investigated people's intuitive beliefs about the TP. We also investigated the relationship between phenomenal TP and perceived vertical. Whether verbally (conceptually) estimating the TP, drawing the TP, or demonstrating the position of the TP, people believe that the TP is close to 45°. In Experiment 3, we found that anchoring influences phenomenal TP and vertical. When accounting for starting position, the TP seems to be best predicted by an intuitive belief that it is close to 45°. In Experiment 4, we show that there is no difference in phenomenal TP and vertical when being tilted about the feet or waist/hips. We discuss the findings in terms of action-perception differences found in other domains and practical implications.