without any reference to physical type, will illustrate that there is ample evidence showing the lack of relation between social habits and physical type.
The serious demand must, therefore, be made that eugenists cease to look at the forms, functions, and activities of man from the dogmatic point of view according to which each feature is assumed to be hereditary, but that they begin to examine them from a more critical point of view, requiring that in each and every case the hereditary character of a trait must be established before it can be assumed to exist.
The question at issue is well illustrated by the extended statistics of cacogenics, of the histories of defective families. Setting aside for a moment cases of hereditary pathological conditions, we find that alcoholism and criminality are particularly ascribed to hereditary causes. When we study the family histories in question, we can see often, that, if the individuals had been protected by favorable home surroundings and by possession of adequate means of support against the abuse of alcohol or other drugs as well as against criminality, they would not have fallen victims to their alleged hereditary tendencies, any more than many a weakling who is brought up under favorable circumstances. Their resistance to the temptations of their environment would have entitled them to be classed as moral heroes. The scales applied to the criminal family and to the well-to-do are clearly quite distinct; and, so far as heredity is concerned, no more follows from the collected data of delinquency than would follow from the fact that in an agricultural community the occupation of farming descends from father to son.
Whether or not constitutional debility based on hereditary causes may also be proved in these cases, is a question by itself that deserves attention; but neither can it be considered as proved, nor do we grant that the selection of delinquents would eliminate all those who possess equal constitutional debility.
Basing our views on the observed fact, that the most diverse types of man may adapt themselves to the same forms of life, I claim that, unless the contrary can be proved, we must assume that all complex activities are socially determined, and not hereditary; that a change in social conditions will change the whole character of social activities without influencing in the least the hereditary characteristics of the individuals concerned. Therefore, when the attempt is made to prove that defects or points of excellence are hereditary, it is essential that all possibility of a purely environmentally or socially determined repetition of ancestral traits be excluded.
If this rigidity of proof is insisted on, it will appear that many of the data on which the theory of eugenics is based are unsatisfactory, and that much greater care must be exerted than finds favor with the enthusiastic adherents of eugenic theories.
