Galton explained this averaging phenomenon in his celebrated 1886 paper “Regression towards Mediocrity in Hereditary Stature.”13 Today, we call this property “regression to the mean.” Regression to the mean is not a causal relationship. Rather, it’s a statistical property of correlated pairs of variables like the heights of fathers and sons. Although fathers’ and sons’ heights are never exactly the same, their frequency distributions are essentially unchanging. This distributional stability generates the Galton regression.
