The phase of public health which may be termed mental health is susceptible to many influences. There is no doubt that successive ages of inbreeding, "racial incest," as Dr. H. M. Friedman calls it, results in a racial tendency toward, or characteristic of, mental instability and predisposition to a neurotic and psychopathic constitution. This is illustrated in the case of the Jews, where their highly developed emotional nature and predisposition to functional insanities may be laid to absence of fresh blood and to close racial inbreeding for many centuries. New blood is essential for racial or individual development.
If the tide of immigration brought to us only the good blood that this country needs, no restrictive examination would be required. But the mentally diseased and defective come in large numbers, and if the vigilance of the nation's sentries were relaxed ever so little, these numbers would swell to an overwhelming flood. Insanity and mental defectiveness are of grave concern from the standpoint of public health. The individual victim is predisposed to crime, is very likely to be not self-supporting, tends to become a complete public charge and, most serious of all, transmits a tainted heredity or actual mental disease to his descendants. Moreover, where physical disease or defect tends toward extinction, mental disease or defect is prolific and both insidious and far-reaching in its ramifications.
Dr. H. H. Goddard has recently made a complete hereditary study of the descendants of an Englishman of good ancestry who contracted an illegitimate union with a feeble-minded girl. A feeble-minded son married a normal woman and from this pair were descended 480 persons. Of these 480 persons, 36 were illegitimate, 24 were chronic alcoholics, 3 were epileptics, 33 were immoral, 8 kept houses of ill-fame and 3 were criminals; 143 were feeble-minded. In all that family only 46 were apparently normal. The legal union of the same ancestor with a normal woman resulted in 496 descendants, of whom but two showed abnormal mentality. Comment on this record is unnecesary. Its lesson should be kept in mind in considering the fact that the alien population of the United States is furnishing considerably more than its proportionate number of feebleminded and insane persons.
More accurate statistics are available for New York state than elsewhere in the country. But while New York is chiefly concerned with the problem of the alien insane and mentally defective, every other state has or will have the same problem in varying degree. It is authentically reported that about one per cent, of the school population of New York City, or about 7,000 children, are distinctly feeble-minded. In addition to these is an equal number of idiots and imbeciles, and the large class of morally defective children and border-line types. Census statistics show that the parents of 30 per cent, of the feeble-minded children in the country at large are aliens or naturalized citizens. In the first line of defence and prevention lies in a rigid primary examination
