The myth of human races

4. Full Blood, Half-Blood, and Tainted Blood

Chapter 4 FULL BLOOD, HALF-BLOOD, AND TAINTED BLOOD "It ain't necessary so." Porgy and Bess I am spending a weekend on Wiggins Lake, in northern Michigan. It is cold, but I feel fortunate that I am not in the eastern United States, which is being battered by what the press calls the worst storm of the century. Inside our cottage I am warm and watching a "thrilling" movie called Tainted Blood. But as the film's plot unravels I become disenchanted with it, because I realize that the movie would be thrilling if I did not know that the three common beliefs about heredity on which it is based are without foundation. What is wrong with Tainted Blood is that there is no such thing. Heredity is not transmitted by blood, and there is nothing inherently special about a boy and a girl just because they are born at the same time. Although they are twins, they are not identical and therefore if one has a murderous disposition, there is no reason to expect the other to behave the same way. These common beliefs are among the many myths that science has rejected but which still persist in the minds of the public at large and obviously also in the minds of some mystery writers. Even today, people know little or nothing about the mechanisms of inheritance.! As a result, they often make vital decisions based on ignorance. Here is but one example: years ago, I lived in a small town in Oregon. My next-door neighbors were friendly, and during one of our initial conversations, I asked if they had children. They said no. The husband added: "Three years ago my wife learned that she was descended from black slaves on her father's side. Her fear of having a Negro baby has kept us from having 33 34 Alain Corcos children." Here was a young couple missing the joys of parenthood because they believed a myth about the appearance of what are commonly called "throwbacks"; in this case, they believed it was possible for them to have a black child. Being a geneticist, I tried to explain to them as best I could that such a thing could never happen. I never learned whether or not I convinced them or if they had children, for I left the town ten months later. Yet, I wonder how many couples' lives have been, and still are, affected by this and the many other myths that surround heredity. This personal encounter with what people believe to be true made me realize that, if we are ignorant of the true nature of heredity , we cannot understand the true nature of the problem of race. Some people persist in believing not only that the characteristics of the child are the result of the blending of the parents blood at conception,2 but also that someone's "race" is inherited, when in fact genes are inherited; genes that dictate skin color, hair, the shape of nose or lips, and so on. According to ancient and fallacious theories of inheritance, the physical means by which transmission occurred were thought to be the commingling and blending of parental substances in the offspring . Something of each parent, popularly referred to as "blood," was assumed to lose its own individuality in the blend, which occurred in the child, and this blending process repeated itself in the children's children and in later descendants. Each person was supposed to have obtained half of his or her inheritance from each parent, one-quarter from each grandparent, and so on in decreasing fractions from remote ancestors. This repeated halving is represented in the following table.3 Chapter Four 35 Table 1. An example of terminology for members of "mixed races" and their constitution in terms of "blood" fractions Parents Offspring Degree of mixture Negro and Mulatto 1/2 European 1/2 Negro European European Terceron 3/4 European 1/4 Negro and Mulatto European Quarteron 7/8 European 1/8 Negro and Terceron European Qinteron 15/16European 1/16 Negro and Quarteron It is interesting to ask why blood was ever thought to be the vehicle of heredity. Perhaps the idea was closely related to the fact that the fluid is absolutely necessary for survival. Since earliest times observers have known that human beings become weaker and sometimes die after appreciable losses of blood. This fact led...