A test of Jensen effects is of nil value as a diagnostic instrument when various good-sized meta-analyses show Jensen effects appear for both genetic effects and environmental effects. Using thought experiments, Flynn (2019) claims that some schooling gains yield Jensen effects, which should not be the case for an environmental effect. However, a meta-analysis (K = 12, total N = 60,993, mean r = 0.13) of schooling gains shows no Jensen effect. Real data trump thought experiments, so it is concluded there is no empirical proof of anomalous Jensen effects for schooling gains.
Keywords: IQ; Jensen effects; Schooling gains.