Does an escaping object look faster? Animacy induced speed overestimation in chasing events

In Michotte's paradigm an object A moves toward, and makes contact with, another object B, which then moves away. If B’s motion is faster than A’s, and starts before the arrival of A, B is perceived to intentionally escape from A. Many studies show an association between speed and animacy, in that objects moving faster are judged as more animated. In our study, conversely, we explored how much a square looks faster when intentionally escaping from another square. We used the method of constant stimuli to measure the speed overestimation of the escaping object in comparison to different levels of speed of a single moving object. We also varied the behaviour of the chasing object, allowing it to move either in a linear or in a caterpillar-like way. Paired comparisons data were analysed using generalized linear mixed-effects models to estimate the PSE in the different conditions. We found a significant overestimation of the escaping object in the fast speed condition, both in the caterpillar-like motion and in the linear motion. These results suggest an interesting connection between specific emotional qualities of motion and its apparent speed, supporting the hypothesis that social causality and animacy are deeply rooted in visual processing.