An early critic of the racial theories of Linné, Kant, and Blumenbach was Johann Gottfried Herder, who in his Ideen zur Philosophie der Geschichte der Menschheit (1784-1791) rejected a division of humanity into races.
Around 1900, critical voices emerged in the German-speaking world that attributed to racial biology a share of the responsibility for increasing anti-Semitism and addressed anti-Semitic phenomena within biology and anthropology. However, the existence of human races was not fundamentally called into question; the criticism was directed specifically against the assumption of an Aryan and a Semitic (Jewish) race and against the valuation of races as higher or lower.
In response to the racist policies of the Nazis, Julian Huxley and Alfred C. Haddon wrote their 1935 book We Europeans: A Survey of Racial Problems, in which they argued that there was no scientific basis for the assumption of different, distinct races of people within Europe. They rejected such classifications based on phenotypical or somatic characteristics and assessments based on them as pseudo-scientific. They demanded that the term "race" be removed from the scientific vocabulary and that instead of human races we speak of "ethnic groups", since these have no biological reference but are defined sociologically. The biological systematization of European human types was a subjective process and the myth of racism merely an attempt to justify nationalism. However, they adhered to the subdivision of the whole of humanity into three major groups, although they suggested that in this case, too, we should no longer speak of races but of subspecies.
Until the 1990s, however, talk of human races remained common in biology. For example, Kindler's Encyclopedia Der Mensch (1982) contains two chapters on "The Racial Diversity of Mankind" and "Racial History and Racial Evolution," and in the Herder Encyclopedia of Biology from 1983 to 1987, reprinted in 1994, the entry Human Races begins with the words: "Like other biological species, today's Homo sapiens (man) is also divided into relatively uniform races with characteristic gene combinations in each case." Accordingly, historian Imanuel Geiss, in his 1988 History of Racism, also called the existence of human races "undeniable in their elementary nature as a real-historical reality."
Population geneticists such as Richard Lewontin and Luigi Luca Cavalli-Sforza have argued since the 1970s that external differences such as skin and hair color, hair texture, and nose shape are merely adaptations to different climates and diets, determined by only a small subset of genes. In fact, North American Indians resemble Europeans more than South American Indians in the external characteristics traditionally used to distinguish races, although they are much more closely related to the latter in origin, and Australian Aborigines, long isolated from the rest of humanity, appear relatively similar to black Africans.
The geneticists used the biological concept of population. To distinguish it from the unsuitable concept of race, however, Cavalli-Sforza defined it for humans more statistically than biologically: "A group of individuals inhabiting a precisely defined space, of whatever kind." A (human) population thus corresponds to the heterogeneous population of an area and not to a (supposedly homogeneous) race. An arbitrarily chosen delimitation is chosen, which does not refer to any typological characteristics. It may be irritating that the old race designations are nevertheless found in human genetic studies. Here, the boundaries of populations were deliberately drawn according to racial theories in order to subsequently disprove them. Cavalli-Sforza writes in this connection: "Of course, one must select the populations to be studied in such a way as to obtain interesting results."
In the Declaration of Schlaining in 1995, a group of scientists declared that the distinction of human races as inherently homogeneous and clearly distinguishable populations had proved untenable due to recent advances in molecular biology and population genetics. The genetic diversity of mankind is only of a gradual nature and does not reveal any major discontinuities. Therefore, any typological approach to the subdivision of mankind is unsuitable. Furthermore, the hereditary differences between different groups of humans were only small compared to the variance within these groups. To assume fundamental genetic differences on the basis of external differences, which are only adaptations to different environmental conditions, is a fallacy. The American Association of Anthropologists issued a statement in 1998 that was consistent in tenor but tailored to the special, historically conditioned circumstances in the USA.
Population genetic studies showed that about 85 % of the genetic variation is found within such populations as the French or the Japanese. By contrast, the genetic differences between the "races" traditionally distinguished on the basis of skin colour are comparatively small, at around 6 to 10 %. In addition, even these supposedly race-specific differences do not reveal clear boundaries when the geographical distribution is examined more closely. The transitions between the "races" (with the exception of the Australian Aborigines) are fluid. These empirical findings, made possible by advances in DNA and protein sequencing, have led the vast majority of anthropologists today to reject a division of humanity into races.
The discrepancy between the difference in external appearance and the uniformity of the genetic make-up is explained by Luca and Francesco Cavalli-Sforza in their book Different and yet the same (1994) as follows:
"The genes that respond to climate [in the course of evolution] affect the external features of the body because adaptation to climate requires, above all, a change in the surface of the body (which is, so to speak, the interface between our organism and the outside world). Precisely because these features are external, the differences between races are so striking that we believe equally glaring differences exist for all the rest of the genetic constitution. But this is not true: With respect to the rest of our genetic constitution, we differ from one another only slightly."
The argument that the genetic variance within a group of Homo sapiens is greater than that between different groups was criticised in 2003 by the geneticist and evolutionary biologist Anthony W. F. Edwards: The statement is only true if one considers alleles at a single gene locus. However, if intercorrelation patterns between different genes and the resulting gene clusters are considered, as they can be obtained using modern methods such as cluster analysis or principal component analysis, the picture is reversed. Edwards argues that it is possible to assign an individual to a specific, biologically defined group if a certain number of genes are considered instead of just individual genes. The article in which he presented his reasoning was called "Lewontin's fallacy" in reference to his colleague. In 2007, his colleague David J. Witherspoon was able to confirm this thesis experimentally by recording several hundred loci simultaneously using multilocus sequence typing. However, it remains questionable to what extent references to the socio-cultural "concept of race" can be derived from these genetic variations.
Edwards' critique was rejected by biological anthropologist Jonathan M. Marks. Race theory sought to discover large clusters of people homogeneous within their own group and heterogeneous to other groups. Lewontin's analysis showed that such groups do not exist in the human species, and Edwards' critique does not contradict this interpretation.
The anthropologist Ulrich Kattmann is of the opinion "that the racial classifications of anthropologists from the beginnings until today are not based on natural science, but originate from everyday ideas and socio-psychological needs". Moreover, they are fundamentally associated with judgmental discrimination and are therefore racist. As an example of the social-psychological conditionality, Kattmann cites the largely arbitrary construction of skin colours. Thus, since Linné, the Chinese have been called "yellow", although their skin is by no means yellow, but corresponds in average pigmentation to that of "white" southern Europeans. Neither are the Indians, the indigenous peoples of America, red.
In the German-speaking world, as the historian of science Veronika Lipphardt writes, racial biology "in the historical retrospect of National Socialism [...] became virtually the epitome of pseudoscience." In this context, "race theorists," namely Gobineau and Chamberlain, are considered "non-scientific," and from them "a direct line" leads to Hitler's Mein Kampf and to the extermination policies of the Nazi state. Since the defeat of National Socialism in 1945, racial biology had been exposed as a false doctrine and overcome. However, two findings speak against this narrative, Lipphardt continues. On the one hand, racial biology in Germany and elsewhere "had been called a pseudoscience long before 1945," and on the other hand, the history of racial biology did not end with the defeat of the Nazi regime, either in Germany or elsewhere. The concept of population offered new possibilities for studying human diversity. A division of humanity into a few groups had survived in various academic and non-academic contexts.
Cavalli-Sforza proposes 38 geographically distinct human populations according to their genetic relatedness and their membership in 20 language families, following Merritt Ruhlen's classification.
Since 2013, Brandenburg - like Thuringia from the beginning - dispensed with the concept of race in its constitution. Article 12(2) of the Constitution of the State of Brandenburg now reads: "No one may be favoured or disadvantaged because of descent, nationality, [...] or for racial reasons." Article 2(3) of the Constitution of the Free State of Thuringia reads: "No one shall be favoured or disadvantaged on account of origin, descent, ethnicity, [...]."
In 2019, the German Zoological Society under Martin S. Fischer, Uwe Hoßfeld, Johannes Krause and Stefan Richter adopted the Jena Declaration, according to which the concept of race is "the result of racism and not its precondition". Other prominent members, such as the criminal biologist and politician Mark Benecke, welcomed the resolution and called for an amendment to Article 3 of the Basic Law. An article in Die Zeit saw the declaration primarily as a political signal at a time when racist ideas were moving further and further into the centre of society. Felix Klein, the German government's anti-Semitism commissioner, also advocated removing the term "race" from the Basic Law, arguing that the term was "a social construct." On the other hand, Andrea Lindholz (CSU), chairwoman of the Bundestag's Committee on Interior and Home Affairs since 2018, expressed strong opposition to deleting the word "race" from the German constitution, calling it a "rather helpless[n] sham debate." A deletion could also complicate the administration of justice, she said. According to Stephan Hebel, however, this "racism of the middle" makes her "exemplary for a behavior that favors racist structures by tolerating them and refuses to resist them."
