It would be nice if all the type O’s lived in one part of the world, and all the type A’s in another. However, this does not happen --much. The various blood groups are found pretty much all over the world. However they are not found in the same frequency everywhere. It was this difference in the frequency of the different blood types that gave the early blood type detectives their first insights into human individuality.

Soon after the ABO blood groups were discovered by Karl Landsteiner in the early 1900’s, scientists began to think about using them as a tool to help study the differences between populations. One of the first to begin using blood type in this manner was a husband and wife team, Ludwik and Hanka Hirszfeld. During World War I, they took blood samples from the soldiers of three continents then assembled in the area of Greece called Macedonia as “The Allied Army of the East.” In reality this army was a hodgepodge of battered contingents and survivors from various Allied nations which did little more than stay put in camp and suffer from constant epidemics. However the Hirszfelds realized that the international nature of this army presented opportunities of examining the serological properties of the blood of a large number of soldiers or civilians belonging to very different races.

They established three categories: One marked by a high percentage of subjects of blood type A and a low percentage of blood type B and which seemed to include the majority of European races (European type); A second showing on the contrary a high percentage of blood type B and a low one of blood type A, comprising Asians and Ethiopians (Asian-African type); and a last category containing approximately equal quantities of blood types A and B made up of Russians, Turks, Arabs and Jews, which they called an intermediate type.

The Hirszfelds invented an interesting and useful tool called the Hirszfeld Biochemical Index and which conveniently lets us express the ratio of blood group A to B in any population. The formula is very simple; you add up the number of blood type A and AB individuals in a population and then divide it by the number of blood type B and AB individuals. As so:

Hirszfeld Biochemical Index = [A + AB] /[B + AB]

Thus, the higher the Hirszfeld Biochemical Index of a population, the more blood type A people in that population over blood type B people in it; the lower, the more blood type B over A. The highest number in the Hirszfeld Biochemical Index (most As, least Bs) was found among the English troops (4.5); the lowest (most Bs, least As) were found in the Indian (0.5) and Vietnamese troops (0.8).

The work of the Hirszfelds would look crude in comparison to later, more sophisticated methods, and it suffers from the problems of all single-gene examinations of human diversity, that is there a no “pure races” to be identified by a single marker. But their discovery, published in 1919, did give rise to a considerable number of subsequent investigations, producing an enormous mass of documents of varying merit.

The arrival of blood typing signaled a new era in physical anthropology, since up to now the field had been limited to many of the physical measurements that I’ve previously described. Here now was a serologic, or blood marker, simple and easy to perform.

One of the first to begin using blood types as an anthropological tool was none other than William Boyd, who I’ve mentioned early in connection with the debunking of racism. In the years after the First World War, Boyd compiled the abundant blood group data coming from transfusion centers throughout the world. With his wife Lyle, during the 1930's, Boyd made a worldwide survey of the distribution of blood types. On this basis, he divided the world population into 13 geographically distinct races with different blood group genetic profiles. He also studied the blood groups of Egyptian and Amerindian mummies.

William Boyd appears to be one of those fascinating people who go on to dominate an entire area of research for a generation. It seems as if his creativity knew no bounds: I’ve already mentioned of his important work with Isaac Asimov used his work with blood types in Races and People to demolish the racist notions then commonly believed in this country during the 1950's; and here we are discussing his work on blood types and anthropology. But William Boyd accomplished much, much more than that. In the 1940’s Boyd noticed that the protein agglutinin in lima bean would agglutinate red cells of human blood type A but not those of O or B; he had in fact discovered that many of the of these blood agglutinins were actually specific to one blood type or another. With Elizabeth Shapely he coined their modern-day name; lectins which is Latin for “to pick or choose.”

Boyd wrote some excellent science fiction (under the name Boyd Ellanby) including two well-known books, 'Category Phoenix' in 1952 and 'Chain Reaction' in 1956. He also authored the Fundamentals of Immunology, one of the first Immunology textbooks for medical students.

By 1950 Boyd had determined about 20 genes for outward appearance traits that are recessive for typical Asians and/or Europeans but homozygous dominant for Africans. These recessive genes include the 6 to 8 genes for light skin color, the genes for blue eyes, gray eyes, blond hair, red hair, thin lips, straight hair, sacral spot, lack of facial hair (beards), narrow nose shape, and some others.

After the Second World War, William Boyd's baton as compiler of blood group data from around the world passed to the Englishman Arthur E. Mourant.

A native of Jersey in the Channel Islands, Mourant received a degree in geology, but as this was Depression-Era Britain, he was unable to find a job. His very strict Methodist upbringing had caused him considerable emotional unhappiness, which he hoped to resolve by becoming a psychoanalyst. To that end he decided to begin by first study medicine.

To avoid the German bombing raids on the capital, his medical school was moved from London to Cambridge, and it was here that he met Ronald Fisher, the most influential geneticist of his day. Fisher, a brilliant eccentric who we will meet again, had been working out the genetics of the new blood groups which were being discovered, and he had become fascinated by the particularly convoluted inheritance of one of them – the Rhesus blood group. Fisher found him a job at once, and the meticulous Mourant spent the rest of his working life compiling and interpreting the most detailed blood group frequency distribution maps ever produced. He never did become a psychoanalyst.

In the early 1600’s Pierre De Lancre, a French witch hunter, speculated why the Basque area seemed to harbor so many witches. He thought the problem stemmed from their great numbers in the various Jesuit missionaries, with all their evangelizing, which had affected them with demons from far-off places that they had carried back to Spain. De Lancre also thought that there early adoption of tobacco use may also be working on their minds. He held Basque women in special contempt, saying that they produced only undersized and cursed children who died.

As Mark Kurlansky recounts in The Basque History Of The World, this last accusation may have had a ring of truth to it, since Basques are renowned among anthropologists for their strikingly high percentage of individuals who have the Rhesus Negative (Rh-) blood type genotype (dd): 60% compared to an average of 16% for the rest of Europe. When a mother is Rh- and she gives birth to Rh+ children, an immune reaction can occur which gives rise to a hemolytic (“blood destroying”) anemia, and often would lead to the death of the child.

Mourant suggested that modern day Basques have other characteristics which may mark them as descendants of the late Paleolithic population of Western Europe: They share a skeletal resemblance to Cro-Magnon man and they are the only Western European people who do not speak a Indo-European language.