206 Evolution and Genetics for mental superiority I should like to add that I am inclined to think that there are considerable individual differences in man that are probably strictly genetic, even though I insist that at present there is for this no real scientific evidence of the kind that we are familiar with in other animals and plants. I will eve venture to go so far as to suppose that the average of the human race might be improved by eliminating a few of the extreme disorders, however they may have arisen. In fact, this is attempted at present on a somewhat extensive scale by the segregation into asylums of the insane and feeble-minded. I should hesitate to recommend the incarceration of all their relatives if the character is suspected of being recessive, or of their children if a dominant. After all, these segregations are based on humanitarian principles, or for our protection rather than for genetic reasons. How long and how extensive that casual isolation of adults would have to go on to produce any considerable decrease in defectives, nor informed person would, I should think, be willing to state. Least of all should we feel any assurance in deciding genetic superiority or inferiority as applied to whole races, by which is meant not races in a biological sense but social or political groups bound together by physical conditions, by religious sentiments, or by political organizations. The latter have their roots in the past and are acquired by each new [end]