By the end of the 19th century, the proposition, "biology determines destiny" was scientific orthodoxy, and prominent scientists such as Louis Agassiz, Samuel Morton, Robert Knox, Herbert Spencer and Ernst Haeckel were busy devising hierarchies of the races in which the "European," or often more specifically "Anglo-Saxon" (for the English, Germans and Americans), were placed at the top, with the other "inferior" races ranked beneath them. For example, Agassiz, a Harvard professor who was America's foremost zoologist of the 19th century, claimed that "the brain of the negro is that of the imperfect brain of a seven months infant in the womb of the white." A whole range of quack sciences such as phrenology and craniometry arose to measure and quantify the differences among individuals as well as races.

Numerous debates about the origin and genesis of humankind raged throughout the 19th century. In the early-mid century, a debate raged between partisans of monogenism and polygenism (i.e., between those who held that all humanity has a common root and those who argued that the different "races" were created separately). The learned associations of the world discussed whether some groups could be classified as human at all, such as the Australian aborigines, who, as late as 1926, were treated as rural pests to be exterminated. By the end of the century, attention had shifted to social-Darwinist theorizing about how the dog-eat-dog ethos of capitalist society ("survival of the fittest") was beneficial for the species.

The following description of the Hottentots was typical of "science" circa 1862:

"the race called Hottentots [are] a simple, feeble race of men, living in little groups, almost, indeed, in families, tending their fat-tailed sheep and dreaming away their lives. Of a dirty yellow colour, they slightly resemble the Chinese, but are clearly of a different blood. The face is set on like a baboon's; cranium small but good; jaws very large; feet and hands small; eyes linear in form and of great power; forms generally handsome; hideous when old and never pretty; lazier than an Irishwoman, which is saying much; and of a blood different and totally distinct from all the rest of the world."
—Robert Knox. The Races of Man: A Philosophical Enquiry into the Influence of Race over the Destinies of Nations

The layering of prejudice is interesting in the above quotation—an Irishwoman, generally considered "white," is the standard for laziness against which the Hottentot is measured. While there was a definite ordering of "races" among whites, in general the "fairer races" were destined to conquer and supersede the "darker races": "Before the go-ahead Dutchmen it was easy to see that this puny, pygmy, miserable race [the Hottentot] must retire...." To Knox and his contemporaries it was axiomatic that race was a determining force in history.

The debates that raged in the scientific community a few generations ago about the hierarchy of "racial superiority" and the destiny of "inferior" races—extinction, extermination, servitude or assimilation—were not the province of a lunatic fringe. They represented the mainstream of scientific thinking. Overtly racist ideas pervaded every aspect of intellectual life: literature, the arts, philosophy and history. Even the most militant sectors of the workers' movement were polluted.

Racism, like other forms of capitalist ideology, reflects the reality of social oppression and exploitation, but it inverts cause and effect. It is bourgeois not only in its historic origins, but also in its social function—providing a rationale for the misery, suffering and injustice which are an inevitable part of the free-market package. Peoples that were enslaved, conquered or dispossessed, are not victims of an irrational social order, but rather doomed by biological predetermination.

Racism is one of the key means by which the economic and social hierarchies of the capitalist world are ideologically "naturalized." At the top of the pyramid, because of their fitness to rule, sit white, bourgeois men. The rest of the world—whether female, black, Asian or even the white male working class—are to the ruling class as children to parents. There has always been a close connection between racism and male supremacist ideology. "According to the anthropologist McGrigor Allan in 1869, 'The type of the female skull approaches in many respects that of the infant, and still more that of the lower races."' As an example of the pervasiveness of such attitudes the authors of Not In Our Genes quote Charles Darwin, the greatest scientist of the 19th century, as remarking: "some at least of those mental traits in which women may excel are traits characteristic of the lower races." Liberals, who dismiss such absurdities as evidence of the scientific backwardness of that age, and comfort themselves with the thought that such vicious ignorance has been transcended, fail to see how, at every stage, science is conditioned by the prejudices of the existing social order.
...And Today

The experience of Nazism discredited the notions of racial superiority in the eyes of millions around the world. Today mainstream science tends to reject race as anything other than a social construct. Those members of the intellectual community who advance "scientific" racist arguments are usually pretty thoroughly rebutted by their colleagues. Yet while crudely racist academics have been pushed to the periphery for several decades, the same groundless "theories" are regularly revived.

In 1969 the Harvard Educational Review published an article by Prof. Arthur Jensen entitled "How Much Can We Boost IQ and Scholastic Achievement?" Jensen argued that the lower scores of American blacks on IQ tests are evidence of their genetic inferiority. Shortly after this, Richard Hernstein, a Harvard psychology professor, "discovered" that the whole working class was genetically predisposed to low IQs. Hernstein's conclusions were no doubt gratifying to the assortment of corporate bigwigs and millionaires sitting on Harvard's governing body:

"The privileged classes of the past were probably not much superior biologically to the downtrodden, which is why revolution had a fair chance of success. By removing artificial barriers between classes, society has encouraged the creation of biological barriers. When people can take their natural level in society, the upper classes will, by definition, have greater capacity than the lower."
—IQ and the Meritocracy, 1973

Hans Eysenek, a British psychologist whose work ran along the same lines as Jensen and Hernstein, asserted that Asians and blacks were intellectually inferior to whites. Eysenek's arguments were embraced by the fascists of the National Front in Britain as "scientific" evidence for their campaign against non-white immigration.

In recent years "socio-biology," which recycles much of the same reductionist mythology, although with a more carefully constructed "objective" cover, has gained wide respectability in the academic community.