But when he used multiple regression to remove the simultaneous influence of height and age, he succeeded in reducing the sex difference by only one-third. He then invoked additional unspecified age and body parameters, claiming that if these could be controlled the entire difference would disappear. David Ankney in 1992 questioned Gould's methodology. He re-examined autopsy data on 1,261 American adults and found that at any given body surface area or height, men's brains are heavier than women's. Admittedly, the brain-size studies present a paradox.
Women have proportionately smaller brains than men but, apparently, the same intelligence scores.
Other theories are that men average slightly higher in general intelligence than do women, and finally that these particular differences in brain size have nothing to do with cognitive ability at all, but reflect greater male muscle mass and physical coordination in tasks like throwing and catching. Similarly, Gould denies that brain weight varies with race. Instead, Michael found errors in Gould's work. For what it is worth, Mongoloids average about a cubic inch more than Caucasoids and over three cubic inches more than Negroids. This result has been corroborated many times since 1980, and by every available technique.