Despite the good environment almost uniformly present, the geniuses in royalty are not scattered over the surface of the pedigree chart, but form isolated little groups of closely related individuals. One centers in Frederick the Great, another in Queen Isabella of Spain, a third in William the Silent, and a fourth in Gustavus Adolphus. Furthermore, the royal personages who are conspicuously low in intellect and morality are similarly grouped. Careful study of the circumstances shows nothing in the environment that would produce this grouping of genius, while it is exactly what a knowledge of heredity leads one to expect.
In the next place, do the superior members of royalty have proportionately more superior individuals among their close relatives, as was found to be the case among the Americans in the Hall of Fame? A count shows at once that they do. The first six grades all have about an equal number of eminent relatives, but grade 7 has more while grade 8 has more than grade 7, and the geniuses of grade 10 have the highest proportion of nearer relatives of their own character. Surely it cannot be supposed that a relative of a king in grade 8 has on the average a much less favorable environment than a relative of a king in grade 10. Is it not fair, then, to assume that this relative's greater endowment in the latter case is due to heredity?
Conditions are the same, whether males or females be considered. The royal families of Europe offer a test case because for them the environment is nearly uniformly favorable. A study of them shows great mental and moral differences between them, and critical evidence indicates that these differences are largely due to differences in heredity. Differences of opportunity do not appear to be largely responsible for the achievements of the individuals.
But, it is sometimes objected, opportunity certainly is responsible for the appearance of much talent that would otherwise never appear. Take the great increase in the number of scientific men in Germany during the last half century, for example. It can not be pretended that this is due to an increased birth-rate of such talent; it means that the growth of an appreciation of scientific work has produced an increased amount of scientific talent. J. McKeen Cattell has argued this point most carefully in his study of the families of one thousand American men of science (Popular Science Monthly, May, 1915). "A Darwin born in China in 1809," he says, "could not have become a Darwin, nor could a Lincoln born here on the same day have become a Lincoln had there been no Civil War. If the two infants had been exchanged there would have been no Darwin in America and no Lincoln in England." And so he continues, urging that in the production of scientific men, at least, education is more important than eugenics.
This line of argument contains a great deal of obvious truth, but is subject to a somewhat obvious objection, if it is pushed too far. It is certainly true that the exact field in which a man's activities will find play is largely determined by his surroundings and education. Young men in the United States are now becoming lawyers or men of science, who would have become ministers had they been born a century or two ago. But this environmental influence seems to us a minor one, for the man who is highly gifted in some one line is usually, as all the work of differential psychology shows, gifted more than the average in many other lines. Opportunity decides in just what field his life work shall lie; but he would be able to make a success in a number of fields. Darwin born in America would probably not have become the Darwin we know, but it is not to be supposed that he would have died a "mute, inglorious Milton": it is not likely that he would have failed to make his mark in some line of human activity. Dr. Cattell's argument, then, while admissible, can not properly be urged against the fact that ability is mainly dependent on inheritance.
We need not stop with the conclusion that equality of training or opportunity is unable to level the inborn differences between men. We can go even farther, and produce evidence to show that equality of training increases the differences in results achieved.
This evidence is obtained by measuring the effects of equal amounts of exercise of a function upon individual differences in respect to efficiency in it. Suppose one should pick out, at random, eight children, and let them do problems in multiplication for 10 minutes. After a number of such trials, the three best might average 39 correct solutions in the 10 minutes, and the three poorest might average 25 examples. Then let them continue the work, until each one of them has done 700 examples. Here is equality in training; does it lead to uniform results?
Dr. Starch made the actual test which we have outlined and found that the three best pupils gained on the average 45 in the course of doing 700 examples; while the three poorest gained only 26 in the same course of time.
Similar tests have been made of school children in a number of instances, and have shown that equality of training fails to bring about equality of performance. All improve to some extent; but those who are naturally better than their comrades usually become better still, when conditions for all are the same. E. L. Thorndike gives[12] the following tabular statement of a test he conducted:
The Effect of Equal Amounts of Practice upon Individual Differences in the Mental Multiplication of a Three-place by a Three-place Number