Some of the most interesting results were obtained when offspring termed second generation animals, derived from alcoholic parents though not themselves treated with alcohol, were mated in various ways. When such individuals were mated with normal individuals, although the litters were small, the results were normal, the normal mate having seemingly counteracted any defects which might have lurked in the second generation animal. On the other hand, out of three matings of second generation animals with alcoholic individuals, two produced still-born young, of which one was markedly deformed, while the third yielded two living young.
However, the most striking results were obtained when two second generation individuals, the offspring of alcoholic parents, were bred together. Although themselves untreated, these individuals, of which 19 matings were made, produced as many or more defective young than did their alcoholic parents. Seven of the matings were unfruitful. The remaining 12 matings gave living litters consisting of 19 individuals in all. Six of these showed various nerve disorders (spasms, epileptic-like seizures, etc.) soon after birth; one was eyeless and otherwise deformed.
Stockard’s Interpretation.—Stockard’s interpretation of his experiments is as follows: “Mammals treated with injurious substances, such as alcohol, ether, lead, etc., suffer from the treatments by having the tissues of their bodies injured. When the reproductive glands and germ-cells become injured in this way they give rise to offspring showing weak and degenerative conditions of a general nature, and every cell of these offspring having been derived from the injured egg or sperm-cell are necessarily similarly injured and can only give rise to other injured cells and thus the next generation of offspring are equally weak and injured and so on. The only hope for such a line of individuals is that it can be crossed by normal stock, in which case the vigor of the normal germ-cell in the combination may counteract, or at any rate reduce, the extent of injury in the body cells of the resulting animal.”
He also believes that various deformities and developmental arrests such as harelip and cleft-palate may similarly be cases of transmission rather than true inheritance, due to the weakening of the germ-cells in some way, or to some lack of full vigor in the uterine environment.
Further Remarks on the Situation in Man.—Returning now to the question of alcoholism in man, it seems in view of the strong circumstantial evidence in the case of man himself, together with the result of experiments on animals, that little doubt remains that excessive alcoholism might result in the production of defective offspring. On the other hand an antecedent degeneracy or neural instability undoubtedly plays an important part in many cases, in the original production of drunkards, and when such occurs, it, as well as the direct effects of alcoholic poisoning, must be reckoned with in the effects on progeny. Studies carried on by Pearson, Elderton and Barrington of the Eugenic Laboratory in London lead these investigators to the conclusion that extreme alcoholism is a result not a cause of degeneracy. That is, the degeneracy is due to the defective stock, not to alcohol. They cite in evidence their records of four thousand school children of alcoholic and of sober parents, which fail to show any unfavorable effect of alcohol on offspring. Some of their critics, however, maintain that they did not choose subjects who were sufficiently alcoholic to give the injurious results that might legitimately be expected among the offspring of excessive drinkers or habitual drunkards.
Where children show a hereditary inclination toward drink, unquestionably one of the strongest factors is the inheritance of the same disposition, the same unstable nervous constitution and its accompanying lack of self-control which led the parent to drink, rather than the inheritance of the effects of the drink on the parent. For in many cases a parent may not become a drunkard until after the children who also become drunkards are born. That the tendency to drink immoderately is frequently due to a strain of feeble-mindedness or epilepsy becomes more evident every day. In many of the so-called “periodical” drunkards, the accompanying features of their periodic attacks of drink-craving, such as clouding of memory, restlessness and depression, are those commonly associated with ordinary epileptic attacks.
Probably Over Fifty Per Cent. of Inebriety in Man Due to Defective Nervous Constitution.—Branthwaite, an English authority on drunkenness, finds that about sixty-three per cent. of the inebriates who come to his notice are mentally defective. In alcoholic insanities heredity is a potent factor. It is coming to be realized more and more that pronounced alcoholism is due in a large percentage of cases, perhaps over half, to a defective nervous make-up. While it is true that many drunkards would not develop without free access to alcohol, on the other hand many would never develop without a bad heredity back of them, which gives them a peculiar nervous constitution that renders alcohol an undue stimulus. In a recent report of the New York State Hospital Commission it is stated that in fifty-four per cent. of the cases of alcoholic insanity, a family history of insanity, epilepsy or nervous disease exists. Thus in the presence of alcohol most of these unfortunates are helpless pawns of a hereditary weakness.
So when the question of alcoholism is viewed from all angles, the children of the human drunkard would seem to run a double menace of misfortune, since they may be subject both to the direct poisoning effects of alcohol and the results of an inheritable degeneracy.
Factors to Be Reckoned With in the Study of Alcoholism.—In any thoroughgoing study of alcoholism in man many factors will have to be reckoned with. First of all there is the question of inherent lack of control. This is probably the principal thing inherited where heredity truly enters as a factor. That example and social environment are important factors in addition to or in place of heredity is clear, too, when we observe that often it is the boys only who take after a drunken father, for there is no evidence that the inherited tendency when it really exists is at all sex-linked. Again, in certain occupations carried on under unwholesome influences relief is frequently sought in alcoholic stimulants, and such custom may easily crystallize into habit. Furthermore, the accustoming young children to doses of alcohol, or the unborn young to alcohol through the body of a drunken mother, may be strongly contributory toward establishing inebriety in certain cases. As we have seen from an abundance of experimental data on animals, moreover, the nurture effects on germ-cells may result in the production of weakened offspring. Such offspring in the case of man are probably less able to withstand temptations of all kinds and hence readily succumb to the habit-forming effects of alcohol if once its use is begun. Lastly, it must not be forgotten that alcoholism in the father usually means poverty and the subsequent accompaniment of malnutrition and neglect of the children, and this in itself may not only account for poor development of the latter, but may also be strongly contributory toward establishing the habit of alcoholism in them.
An inherent bias plus most of the other conditions just enumerated is the not unusual lot of the offspring of drunkards.