Early-Developing Causal Perception is Sensitive to Multiple Physical Constraints

If an object A moves until it is adjacent with a stationary object B, at which point object A stops and object B begins moving, adults and infants 6 months of age and older perceive that A caused B to move. These “launching” events correspond to real-world collisions, which are governed by Newtonian mechanics. Previous work showed that infants were sensitive to Newtonian constraints on relative speed. Here, we show that infant causal perception is sensitive to other physical constraints on collision events as well. Infants habituated to a launching event will dishabituate to an event in which object B moves at a 90° angle relative to object A, but not to a rotated version of the launching event. This selective dishabituation was not found for non-causal events. The results suggest that early-developing causal perception is sensitive to the many physical principles of real-world collision events.