The First Genetic Marker: Blood Groups and Human Heredity, 1900-1950

Abstract

Presentation slides for lecture delivered by William H. Schneider, PhD (Professor Emeritus of History and Medical Humanities, Indiana University Indianapolis) on November 18, 2025. This presentation was based on Dr. Schneider’s book of the same title published by Palgrave Macmillan in 2024. It describes the rapid establishment of blood group research around the world in the first half of the twentieth century which was driven by the early discovery that they were inherited by Mendelian laws. When ABO blood types were found to be unevenly distributed among various human populations, over 1,000 studies were conducted by 1939 (on over a million subjects) to determine if blood groups were genetic markers of race, disease, and behaviors such as crime, insanity, and temperament. They were largely unsuccessful, but the history of this research reveals much about the development of new medical research fields and the seduction of genetic determinism. Presentation recording available online: https://purl.dlib.indiana.edu/iudl/media/v63f95rz3x