Charles Benedict Davenport

“ And we can not escape the conclusion that the gradual acquisition of social traits by the normal child follows much the same road as the evolution of social man from non-gregarious apes. But, there are men who never develop these social traits. And if we study the pedigrees of such men carefully (and many of them have been studied for six or seven generations) we trace back a continuous trail of the defects until the conclusion is forced upon us that the defects of this germ plasm have surely come all the way down from man's ape-like ancestors, through 200 generations or more. ”

“ This brings us to the subject of the control of mental defectiveness. We see at once that there must have been at work, even in prehistoric times, a sort of natural control by the elimination of those incapable of meeting the ever-increasing complexities of "advancing civilization."
As man spread to the north those strains that had not acquired the trait of hoarding for the winter mostly perished of cold and hunger; those strains that had not acquired the sense of property rights and tended to invade the stores of others were always in danger of being cut off. ”

“ Now there is a well-known biological principle that "ontogeny recapitulates phylogeny"—that the child in his development passes through the same series of physical and mental stages that the adults did in the successive generations of the race's development. ”

“ This germ plasm that we are tracing remains relatively simple; it has never gained (or only temporarily, at most) the one or the many characteristics whose absence we call, quite inadequately, defects. Feeble-mindedness is, thus, an uninterrupted transmission from our animal ancestry. It is not reversion; it is direct inheritance.
To summarize: Man is evolving and in that evolution he has lost some physical traits and gained some mental ones. But neither in their losses nor in their gains have all strains evolved to the same extent. ”

“ So we may infer that man's remote ancestors did not go in their adult stage beyond the point where this infant-man is now. Indeed, the adult apes, nearest allies of our ancestors, show the same inability to talk, to dress, to regard property rights and to be gentle and considerate toward others that the infant shows. ”

“ He is cruel to the cat, appropriates to his own use the property of others, and insists vehemently upon having what he wants at whatever inconvenience to another. He is now a low-grade imbecile without moral ideas. ”

“ The legislatures of six of the United States have already voted to permit the sterilization of defective persons. But it is doubtful if the "more advanced" public is altogether ready for such operations. A less drastic, but not less effective, method is the segregation of the defective strains during the entire reproductive period. ”

“ He will prove himself not to be "feeble-minded" if, as he approaches puberty, all of these and the other socially important undeveloped conditions prove, under fair culture, capable of development up to the corresponding "normal" conditions. Defectiveness is thus a persistent infantile condition of one or more characteristics; a failure of certain socially important traits to develop. ”

“ Before we can answer the question as to the "cause" of feeble-mindedness it is desirable to get a clear definition of the term. As a matter of fact, very diverse definitions have been offered. An old legal formula is as follows: "He that shall be said to be a sot and idiot from his birth is such a person who can not count or number twenty pence, not tell who was his father or mother, nor how old he is, so it may appear that he hath no understanding or reason what shall be for his profit or what for his loss ”