Martin Luther King, Jr. acknowledged the battle against the false science of white supremacy in his 1963 sermon “Love in Action.” He explained that the motivation for slavery was rooted in three sins. The first was greed. The second was false doctrine. The third was science.
Men convinced themselves that a system which was so economically profitable must be morally justifiable. They formulated elaborate theories of racial superiority. Their rationalizations clothed obvious wrongs in the beautiful garments of righteousness. This tragic attempt to give moral sanction to an economically profitable system gave birth to the doctrine of white supremacy. Religion and the Bible were cited to crystallize the status quo. Science was commandeered to prove the biological inferiority of the Negro. 
But then King found hope in changing attitudes. He pointed to the work of Ruth Benedict, Margaret Mead, and Melville J. Herskovits who were proving that there were no innate biological differences between the races. He called the old science of white supremacy “pseudo-scientific” and belittled racists for not knowing that it had been discredited.
Pressed for a justification of their belief in the inferiority of the Negro, they turn to some pseudo-scientific writing and argue that the Negro’s brain is smaller than the white man’s brain. They do not know, or they refuse to know, that the idea of an inferior or superior race has been refuted by the best evidence of the science of anthropology. Great anthropologists, like Ruth Benedict, Margaret Mead, and Melville J. Herskovits, agree that, although there may be inferior and superior individuals within all races, there is no superior or inferior race. And segregationists refuse to acknowledge that science has demonstrated that there are four types of blood and these four types are found within every racial group. They blindly believe in the eternal validity of an evil called segregation and the timeless truth of a myth called white supremacy. 
The attempt to discredit white supremacist racial science had already begun in the 1930s through the work of Frans Boaz, whose books were burned in Nazi Germany.  He had helped Frederick Ward Putnam to develop the display of evolving races at the 1893 Columbian Exposition, but regretted it, and went on to become an opponent of scientific racism. He also held several debates with Madison Grant (author of “Hitler’s Bible”). One of his students (mentioned by King) was Ruth Benedict.
Benedict was an anthropologist who, along with Gene Weltfish, wrote a 1943 booklet (“Public Affairs Pamphlet No. 85”) entitled The Races of Mankind, which explained why the science of white supremacy was false. It sold 750,000 copies and was passed out to the military, Sunday schools, classrooms, and other places where it could be influential in society. (The booklet was even made into a short film as a way to encourage black and white autoworkers to get along.)  Writing at the height of World War II, she described how people of all races were fighting in a 34-nation alliance “against one enemy.”  Her pamphlet then went on to explain that “the Bible story of Adam and Eve, father and mother of the whole human race, told centuries ago the same truth that science has shown today: that all the peoples of the earth are a single family and have a common origin.”
If only the world would have remained true to this biblical teaching right from the beginning….
 Martin Luther King, Jr., “Love in Action” 1963 sermon found in Strength to Love (Boston: Beacon Press, 2019), 37.
 Ibid., 38.
 R. A. Pathe, “Gene Weltfish: 1902-1980,” as found in Women Anthropologists: Selected Biographies, eds. Aisha Khan, Jerrie McIntyre, Ruth Weinberg, Ute Gacs (New York: Greenwood Press, 1988), 375.
 “The Brotherhood of Man – Post-WWII Animated Cartoon Against Prejudice and Racism (1946),” YouTube, Nov. 12, 2012. https://www.youtube.com/watch?v=Fnrxbkajy9M&feature=emb_logo.
 Ruth Benedict and Gene Weltfish, The Races of Mankind (Eastford, CT: Martino Fine Books, 2020), 1. (Later, this booklet would be suppressed for being a source of communist propaganda. It would be subjected to the inspection of Joseph McCarthy and his Un-American Activities committee. Gene Weltfish would be blacklisted and even lose her teaching position at Columbia University. From: A. Campbell, “Influence and Controversy. The Races of Mankind and The Brotherhood of Man.” Social Welfare History Project. http://socialwelfare.library.vcu.edu/eras/wwii-1950s/influence-controversy-races-mankind-brotherhood-man/.
 Benedict, The Races of Mankind, 3.