The layman's concept of race is based on differences in the appearance and behavior of the different groups. This attitude, Boyd1 points out, has been unconsciously retained by many scientific workers. In recent years there has been a trend on the part of both geneticists and physical anthropologists to apply genetic methods to the problems of classification of man. Fairly adequate information about the mode of transmission of blood group genes was obtained before any information equivalent in amount or value was obtained about the genes affecting physical appearance. The genes which could be more useful in anthropology are the blood group genes.
L. and H. Hirshfeld showed in 1919 that agglutinogen A (characteristic of group II) predominates greatly over B in the population of northern Europe and that agglutinogen B (characteristic of group III) predominates in Asia and Africa. The two are about equal in certain intermediate races.
USE OF BLOOD GROUPS IN HUMAN CLASSIFICATION. JAMA. 1950;144(9):765. doi:10.1001/jama.1950.02920090039014