"....the evidence that brain size is correlated with intelligence, and that blacks have smaller brains than whites. But the brain size difference between men and women is substantially greater than that between blacks and whites, yet men and women score the same, on average, on I.Q. tests. Likewise, a group of people in a community in Ecuador have a genetic anomaly that produces extremely small head sizes and hence brain sizes. Yet their intelligence is as high as that of their unaffected relatives."