The spatiotemporal distinctiveness of direct causation.

The launching effect, in which people judge one object to have caused another to immediately move after contact, is often described as the prototype of direct causation. The special status of this interaction may be due to its psychophysical distinctiveness, and this property may be the origin of the formation of causality as a conceptual category. This hypothesis was tested by having participants judge the relative similarity of pairs of events that either had no spatial gap or delay (direct launching) or had small gaps and/or short delays. Direct launching was much easier to discriminate from launches involving small gaps or delays. In a follow-up experiment, participants made similar judgments for a noncausal event.