I30 THE TREND OF THE RACE 



types of humanity. On the other hand, those who are mentally 

 defective or subnormal tend, through their lack of restraint and 

 foresight, to be unusually prolific. The records of the Jukes, 

 Kallikaks, Nams, Hill Folk, Tribe of Ishmael and other notorious 

 defective strains show that these degenerates are distinguished 

 for unusual fecundity which more than offsets their high infant 

 mortality. Dr. Wilmarth in reporting on some cases of the 

 transmission of mental defect has incidentally chosen cases which 

 illustrate the high fecundity which is only too prevalent in this 

 class: "Two children from one family are under our care. From 

 the sheriff, who brought the children, and an intelligent neighbor, 

 I learned that the mother was weak mentally. The father seldom 

 worked but managed to raise his family on what he could obtain 

 in other ways. Not one of the eighteen children was a desirable 

 member of society. The girls drifted into disreputable lives; the 

 boys were idlers and thieves with no moral sense. I know a 

 couple in Pittsburgh, Pa., whose nine children were all idiots of 

 low grade. A family in eastern Wisconsin, the father and mother 

 are both feeble-minded; at least 7 of the 8 children are imbeciles; 

 5 we have cared for. A couple in this state have nine children, all 

 subnormal, and there are several, to my knowledge, in collateral 

 branches of the family. One feeble-minded woman, now removed 

 from the state, had by different men 18 children in 19 years, she 

 alleges. I have seen only three of her children. These were 

 feeble-minded and especially defective in moral sense." ^ 



1 Dr. C. T. Ewart {Jour. Mental Science, 56, Oct., 1910) states that "Dr. Ettie 

 Sayer, in the course of her work for the London City Council, studied the family 

 history of 100 normal families and 100 families where mental defectives were found. 

 The normal families averaged five in number, while families showing abnormality 

 averaged 7.6, or nearly one-third as many more." It is not altogether dear from 

 the account how the average number in the normal families was arrived at. If 

 100 families were chosen and the average number of children computed, it would 

 not form a fair basis of comparison with the fecundity of the stocks containing 

 mental defectives. Taking the mental defectives, or any lot of individuals however 

 characterized, it is probable that they will be found to come from families of 

 more than the average size. If we draw 100 people at random from the general 

 population, we are apt to get a preponderating number from families of relatively 

 large size, since these present the largest number of individuals to draw from. If 

 we take 100 families and find the average number of individuals they contain, this 



