Blood Purity: How a Bizarre Obsession Advanced Science

June 2, 2013— -- Already years before the Nazis came to power, German scientists were propagating theories about blood purity. Though this obsession led to bizarre and dangerous theories about superiority and personality traits, it also led to medical breakthroughs.

For the majority of humanity, the outbreak of World War I was a catastrophe on an unprecedented scale. But for Ludwik Hirszfeld, it turned out to be a stroke of good fortune.

Together with his wife, Hanna, the German doctor ran a bacteriology lab in Thessaloniki, Greece, where he had nearly unlimited access to human test subjects -- the French, British, Italian, Russian and Serbian soldiers who made up the multinational Army of the Orient, stationed in this port city in northern Greece and hemmed in by German troops during the so-called Balkans Campaign of the war.

In the interest of conducting one of the largest field studies in medical history up to that point, Hirszfeld approached these languid POWs with a needle and a request to draw their blood. The doctor knew just how to approach each of the different nationalities to sweeten the deal and get a soldier to participate in his large-scale experiment.

"With the English, it was enough simply to comment that this was being done for scientific purposes," Hirszfeld recalled in his memoirs. For his "French friends," on the other hand, the resourceful doctor offered tips on whom they could "sin with impunity" with based on their blood type. He also found it easy to convince the Senegalese soldiers who were there as colonial troops in the French army. "We told them the test might be connected with possible time on leave," Hirszfeld wrote. "And black hands stretched toward us in no time at all."

In the space of just a few months, Hirszfeld enthused, it had been possible to achieve what would otherwise have taken years -- the identification of the blood types of around 8,000 soldiers from a wide range of countries. Once the doctor, long based in the western German city of Heidelberg, had analyzed his data, he believed he had made a groundbreaking discovery: "Blood group A was associated mainly with the white, European 'race,' while blood group B was attributed to the dark-skinned 'races,'" writes Swiss historian Myriam Spörri in a recently published book on the cultural history of blood-group research.

Hirszfeld and his colleague Emil von Dungern had developed the blood type groupings A, B, AB and O, now in wide use internationally, in 1910. Before them, in 1901, it was Karl Landsteiner who first discovered that red blood cells possess a variety of antigens.

Focused on 'Blood Purity'

The Nazis forced Hirszfeld, a Jew, into the Warsaw Ghetto in 1941, although he survived. The blood researcher has generally been free of any suspicion that racist motivations guided his work. Spörri, though, reaches a different conclusion.

The fields of research Hirszfeld founded were "eugenically charged" from the start, the Swiss historian concludes. Even during his internment, Spörri writes, Hirszfeld gave lectures in which he stated "that blood group distributions among Jews and the 'host peoples' they lived among were nearly identical."