Not surprisingly, the bones within which brains reside can be markedly different. A child could distinguish between the skulls of Eskimos and Laplanders as easily as he could tell cucumbers from zucchinis. The skulls of Australian aborigines have characteristics not found in any other race, but common in fossils of pithecanthropus. The bones of the skull are twice as thick as those of any other race (10 mm v. 5 mm), and the skull has heavy frontal and parietal ridge lines typical of pithecanthropus. The teeth and lower jaws of aborigines are also larger than those of other races, and more similar to those of our remote ancestors.
It is little known that Africans have identical twins twice as frequently as Europeans—who in turn have them twice as frequently as Asians. Some African populations have identical twins seven times as frequently as whites. Blacks also have shorter gestation periods than whites or Asians. By the 39th week, 51 percent of black babies have been born but only 33 percent of whites. By the 40th week, the figures are 70 percent and 55 percent. Shorter gestation seems to be a characteristic of blacks that is independent of social status or access to medicine.
Prof. J. Philippe Rushton of the University of Western Ontario, who has probably studied maturation rates more extensively than anyone else, reports that rapid development of blacks continues after birth. Many African and black American newborns can hold their heads up whereas white and Asian newborns almost never can. The average age at which black children walk is 11 months, compared to 12 months for whites and 13 months for Asians.
Prof. Rushton has found that blacks reach sexual maturity earlier than whites. By age 12, 19 percent of black girls have full development of breasts and pubic hair, whereas only two percent of white girls do. Black American women menstruate at an earlier age than white women. They then go on to have sexual intercourse for the first time at an average age that is two years younger than that of whites.
Although it has long been the subject of ribald speculation, the races do appear to differ in the size of their sex organs. The best data seems to have been gathered in 1979 by P. H. Gebhard and A. B. Johnson. They actually took measurements and found that popular myths are correct: blacks are better endowed than whites. In extensive interviews, they also found that black men at least report themselves to be less restrained than whites in their willingness to commit adultery, likelihood of frequenting prostitutes, and number of sexual partners.
Somewhat comparable differences have been found between whites and Asians. Even after controlling for body size, Danes have testes that are proportionately twice the size of those of Chinese. Whites are also estimated to produce twice the number of spermatozoa per day as Asians.
Earlier maturation and early sexual activity among blacks may have a biological price. In the United States, blacks, on average, can expect to die six years sooner than whites. Higher homicide, accident, and disease rates contribute to this difference, but it is entirely possible that blacks may also have a naturally shorter life span.
Medical Differences
Our society generally keeps quiet about physical differences between the races, but information about them occasionally surfaces in news stories about disease. Alcoholism, for example, appears to strike different races at different rates. Asians (and American Indians to whom they are related) react more strongly than whites to alcohol. More Asians than whites show an allergic reaction to alcohol and therefore do not drink, whereas many American Indians seem to have a biological predisposition to alcoholism. Curiously, Asians are twice as likely as whites to suffer from motion sickness.
In the United States, the most frequently reported medical differences concern blacks and whites. It is well known that only blacks suffer from sickle-cell anemia, for example, a condition that helps the body resist malaria, and is therefore a benefit in the African jungle.
Most of the known medical differences, however, seem to disadvantage blacks. Black women are twice as likely to have strokes as white or Hispanic women, and they suffer more damaging aftereffects. Blacks are three to four times more likely to have dangerously underweight babies. This could be due to bad diet, poor general health, or scant medical care, but some studies indicate that even when these factors are equalized, black babies are more likely to be underweight.
Kidney disease is eighteen times more common among blacks than whites. Left untreated, AIDS kills blacks more rapidly than it does whites or Hispanics, and blacks do not respond as well to the drug AZT as do patients of other races. Glaucoma strikes blacks five times more often than it does whites. It sets in earlier, and the likelihood of getting the disease does not appear to be affected by social status or availability of medical care.
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