 Standard non-relativistic quantum mechanics of finite degrees of freedom predicts the famous EPR correlations (see entry on  the Einstein-Podolsky-Rosen argument in quantum theory),  which have been observed in sophisticated physical measurements (see entry on  Bell’s theorem).  These correlations are between events that are spacelike separated (hence causally independent according the special theory of relativity). Thus, they can serve as evidence to assess the status of the Common Cause Principle: These EPR correlations should have common causes if the Common Cause Principle describes the physical world correctly.