Infant mortality: the focus of scientific debate

The official Reports of 1903 and 1904 only represented the initial exchange of hostilities between hereditarians and environmentalists. The post-Boer War inquests proved to be the start of a continuous battle by appeal to the evidence as each side sought to show greater congruence between its own theory and the facts of poverty: the associated class-differential patterns of mortality and fertility. Inspired by Galton's attribution of a eugenic scale of evaluation to Booth's social class scheme, there soon appeared eugenic studies, purporting to measure the reproduction of the various social groups within the nation.

In a research report published in 1906 David Heron, one of Pearson's assistants at the UCL (University College, London) Biometric Laboratory endowed by Galton, attempted the first ‘thorough’ eugenic treatment of the subject: ‘On the relation of fertility in man to social status changes in the last fifty years’. In Heron's study, the main empirical undertaking consisted of producing correlation coefficients between various indices constructed from official sources, relating to the observable socio-demographic traits of the populations of administrative districts. Of course, the assumption involved in such a procedure, for any causal inference to be validly derived, was that the attributes were formally independent.