Amir Teicher's book surveys the uses of Mendelism in the social and human sciences, medicine, eugenics, and racial policy in Germany, up to and during the Third Reich. It covers an impressive range of disciplines and professions, including genealogists, biology teachers, anthropologists, psychiatrists, physicians, bureaucrats, and politicians.

Teicher finds that in the 1910s and 1920s, most genealogists were uninterested in Mendelism, despite the demand from geneticists for pedigree data and the opportunity to enhance their discipline's scientific status. Psychiatrists, in contrast, had already been investigating how mental illnesses run in families and embraced the hunt for Mendelian genes for mental traits, though without unqualified successes. Genes for bodily traits were easier quarry and helped push physical anthropology away from typological conceptions of race and toward a view of races as bundles of co-occurring characteristics. These could be inherited independently and recombined in various ways when races mixed. Nordicists and Aryan supremacists resisted this change, but also found aspects of Mendelism they could use to enhance their own scientific credibility. Their old fears of racial dilution and deterioration could now be reconceptualized in terms of Jewish or other dangerous or alien genes that lurked as unexpressed recessives in many Germans. Indeed, the bugbear of the hidden deleterious recessive is the leitmotiv of this book and the most persuasively presented element of Social Mendelism.

Under Nazism, the 1933 Sterilization Law signaled its scientific legitimacy by targeting people with traits that arguably were Mendelian. Educational films, textbooks, and biology curricula hammered home the importance of Mendelism and the association between recessive traits and dangerous diseases or racial characteristics. The Nuremberg Laws of 1935, which regulated the status and marriages of Jews and half- or quarter-Jews, also had a Mendelian connection: unpublished proposals and drafts cited Gregor Mendel in support of various legislative options. They did not all make it into the final language, which omitted Mendel and used an odd mix of religious and cultural criteria for Jewishness along with the hereditary ones, but Mendelism did enter into the legislative process.

Similarly, Mendelism was a hidden factor in the Final Solution, particularly when the treatment of half- and quarter-Jews was debated. An argument for keeping them alive but sterilizing the half-Jews and forbidding the quarter-Jews from marrying Aryans cited, “the danger of transmitting Jewish characteristics in accordance with Mendel's laws” (198, quoting Hans Lammers, the head of the Reich Chancellery). The opposite solution for the quarter-Jews also invoked Mendel: allowing them to marry Aryans so as to dilute their recessive genes within the larger population.

So what does this all add up to? Does it rise to a level worthy of being named a new “-ism”? Did Social Mendelism influence Nazi ideology and policy, or merely cover its naked racism and cruelty with a fig leaf of scientific respectability and rationalize foregone conclusions? And what exactly counts as Social Mendelism?

On the social side, the book covers more than three tumultuous decades of German history and extends into the post-1945 period and areas outside of Germany as well. On the Mendelism side, it covers the period fifty to eighty years after Mendel's publication, when the field of genetics was growing and changing rapidly. Complicating the matter further, the focus here is on social disciplines not all up to date with genetics or using genetics selectively and tendentiously. Is any social application at all of any aspect of Mendelism at any time to be counted as Social Mendelism and lumped together with Nazism? Teicher's desire to apply the term widely is sometimes at odds with his efforts to capture and characterize the historical moment.

The stated definition of Social Mendelism (18) tries to do both. It emphasizes the aforementioned fear of hidden recessives and independent assortment of racial traits, which the book documents well in pre-1945 Germany, and which can be found internationally and postwar as well. But it also includes ideas from genetics, population genetics, and evolutionary theory from various decades and national contexts that never really went together and were not all associated with Mendel. Why throw in The Selfish Gene (Richard Dawkins, 1976) and gene-level views of evolution, for example?

The concept of Social Darwinism, in comparison, is easier to define and to apply widely. It uses just a few, very general biological principles—“the struggle for limited resources, nature's selection powers and the ultimately benevolent outcome of free competition,” as Teicher phrases them (5), and they can be associated with Darwinism across different historical contexts. They also guide policy in specific directions.

Social Mendelism seems to offer less guidance, and the political uses Teicher explores are mostly rhetorical. Do all the appeals to Mendel's authority or references to Mendel's laws in policy drafts really make a difference in the outcomes? Was Social Mendelism, however defined, a sufficient or even necessary cause of the discriminatory laws and extermination programs? Teicher tends to avoid talk of causes in favor of much weaker sorts of influences. Policies were “informed by and imbued with Mendelian suppositions” (10), he says, and Mendelism “provides an overall framework” (8) and an “independent toolbox for thinking about the sociobiological dynamics leading from the past through the present to the future” (5), as opposed to suggesting particular thoughts, values, or policy directions, either to the historical actors or to us today.

Consider, for example, the references to Mendelism in connection to the Nuremberg Laws. Teicher concedes that “These references may seem superficial, attesting more to the wish to clothe policy-making procedures in biological garb.” He argues, however, that “All those involved had to become acquainted with Mendelian teaching and find ways to integrate their belief system and suggestions with it.” Mendelism thus became part of the Nazi “reasoning apparatus” (176). In that case, should the causes and motivations for Nazi policies not be sought in the total belief system and reasoning apparatus? Why reduce everything to the Mendelian part and name the whole “-ism” after it?

Finally, to what extent is Social Mendelism still the same thing when we remove it from that total belief system and reasoning apparatus, or change the science or the social goals? The book elides quite a few scientific, social, and moral distinctions as it subsumes Weimar era and earlier German eugenics, psychiatry, and physical anthropology, along with British and American eugenics movements, under the same category as Nazism. It does not let postwar genetics completely off the hook, either. In the epilogue, Teicher acknowledges that geneticists repudiated Nazism and racism and called for science to be apolitical, but he treats this as a self-serving and misleading move. It could not eliminate the field's past social and political meanings and associations, only mask them. Those persist like hereditary taints, of which we must always be wary.