Blood Group Serology and “Race”: Looking Back to Move Forward

•Race is a social, not biological, construct.•Seroanthropology is defining racial groups through blood group antigen frequencies.•Seroanthropology has been used for racist purposes.•Blood group antigen frequency data helped disprove the biological race concept.•The history of seroanthropology informs race-conscious transfusion medicine practice. Less than a decade after the discovery of the ABO antigens as a Mendelian inherited trait, blood group antigen frequencies were first used to define racial groups. This approach, known as seroanthropology, was the basis for collecting large amounts of blood group frequency data in different populations and was also sometimes used for racist purposes. Ultimately, population geneticists used these data to disprove race as a biological construct. Through understanding the history of seroanthropology, and recognizing the harms of its lingering presence, healthcare providers can better practice race-conscious, as opposed to race-based, transfusion medicine.