DIFFICULTIES IN THE STATISTICAL PROCESS: TWO EXAMPLES IN KARL PEARSON’S WORK

Investigating the causes of statistical relations is a complex task and the statistician should be careful to ensure a proper measurement and analysis has been conducted, as well as checking the logic and causality of the relations identified. This paper is a critical review of Pearson’s use of statistics in two studies on Jewish people. In one paper, he demonstrates that intelligence is gender-related in Jewish children and in another he assigns the highly correlated cephalic index of Jewish and Gentile people to a rapid assimilation of the former due to inter-marriage. Later authors have found weak points in each of Pearson’s argumentations: the use of an inappropriate measurement method and the insufficient investigation of causality. Because of the issues in argumentation, Pearson’s results become unreliable in both studies and may be considered “cautionary tales” when seeking to explain statistical relations.