April 27 marks the 80th anniversary of the death of Karl Pearson, who contributed to statistics the correlation coefficient, principal components, the (increasingly-maligned) p-value, and much more.

Pearson was one of a trio of founding fathers of modern statistics, the others being Francis Galton and Ronald Fisher.  Galton, Pearson and Fischer were deeply involved with eugenics, a social philosophy that advocated suppression of reproduction among the “unfit” and encouragement of reproduction among the “fit.”

Francis Galton (correlation, regression to the mean, survey methods) coined the term “eugenics” after reading “The Origin of Species” by his half cousin, Charles Darwin.

Galton focused much of his research and scientific publications on eugenics, and became the Honorary President of the British Eugenics Society.  Karl Pearson was a protege of Galton who assumed the Galton Chair of Eugenics at the University of London.Â

It was Pearson who saw society as “an organized whole, kept up to a high pitch of internal efficiency by insuring that its numbers are substantially recruited from the better stocks, and kept up to a high pitch of external efficiency by contest, chiefly by way of war with inferior races.”

R.A. Fisher (design of experiments, discriminant analysis, F-distribution) joined official committees to promote eugenics and, in his “Genetical Theory of Natural Selection,” focused on eugenics and what he saw as the need for the upper classes to boost their fertility.

The close ties between eugenics and statistics dissolved as statistics branched out in the service of all scientific disciplines, and eugenics itself was discredited through its close association with Nazi Germany.

The statistical methods that were developed in the service of eugenics are all sound and have survived the test of time. Though they are but a long-faded shadow in the eyes of modern statisticians, the genetic theories and social policies that motivated the founding fathers of statistics are, like Jefferson’s views on slavery and Churchill’s on Indian independence, a jarring reminder that illumination and truth often come bundled with a measure of darkness.