ALCOHOL, DISEASE, AND HEREDITARY DEFECTS 287 



But granting these groups dealt with are not representative 

 of the general population, this fact is irrelevant, as Pearson has 

 urged, so long as it has not been shown shown that for each group 

 the alcoholic and non-alcoholic parents do not belong to heredi- 

 tarily differentiated classes. Pearson claims that his critics have 

 not shown that this is the case, and he has furnished evidence that 

 so far as wages and choice of trades are concerned, there is no 

 marked difference between the alcoholic and non-alcoholic sec- 

 tions. It may be urged, a priori^ that if a group which works 

 against a handicap of alcohol attains an efficiency equal to that 

 of another group not so handicapped, the former must be the 

 better hereditary material, but we have no statistical proof of 

 this in the present case. 



Where we are dealing with the parents of defective children, 

 as in the Manchester data, there is of course the possibility, 

 especially in the light of the experiments of Stockard, that the 

 sober parents produce defective children because they are of 

 defective stock, while a part of the alcoholics do so because they 

 are alcoholic. These possibilities are mentioned not as a criticism 

 of the memoir in question, but as showing the extreme difficulty of 

 solving biological problems which are complicated by so many 

 social factors. As the studies of extreme alcoholism have ihown, 

 extreme alcoholism itself serves to distinguish biologically one 

 class from another. In view of the graded character of mental 

 defect at what point does alcohol cease to have this segregating 

 effect? An occasional or moderate use of alcoholic beverages is 

 perhaps no more indicative of mental peculiarities than being a 

 teetotaler, if as much. But as the use of alcohol increases it comes 

 to be more of a mark of a hereditarily defective stock. It is not 

 improbable that, as Pearson suggests, the parents of the Edin- 

 burgh and Manchester school children failed as a rule to develop 

 that degree of alcoholism which is associated with mental defect. 

 The apparent discrepancy between the results of the First Study 

 and the Studies on Extreme Alcoholism is explained on the ground 

 that "the mentally defective became extreme alcoholists, ine- 

 briates in constant conflict with the police because the mental de- 



