Human causal perception in a cube-stacking task

In intuitive physics the process of stacking cubes has become a paradigmatic, canonical task. Even though it gets employed in various shades and complexities, the very fundamental setting with two cubes has not been thoroughly investigated. Furthermore, the majority of settings feature only a reduced, one dimensional (1D) decision space. In this paper an experiment is conducted in which participants judge the stability of two cubes stacked on top of each other. It is performed in the full 3D setting which features a 2D decision surface. The analysis yield a shape of a rotated square for the perceived stability area instead of the commonly reported safety margin in 1D. This implies a more complex decision behavior in human than previously assumed.