34 



The Journal of Heredity 



the question was not reall\- made a 

 crucial one among j^enetists until the 

 publication of three bulletins from the 

 Gal ton Laboratory of London, devoted 

 largely to an attack on exactly this 

 feature of recent American work in 

 eugenics. 



In the first one,^ Dr. Heron, the 

 assistant director, devoted himself 

 wholly to a destructive criticism of 

 studies which considered mental defect 

 from a Mendelian \-iewpoint — which 

 assumed, in short, that feebleminded- 

 ness was a unit character and so behaved 

 in inheritance. He was answered* by 

 some of the men he attacked ; but as the 

 controversy was fairly well aired in the 

 daily as well as the scientific ]:)ress, it 

 will not be renewed here. 



Following this came another contri- 

 bution from London,^ in which measure- 

 ments of the intelligence of school 

 children in Stockholm were presented to 

 l)ro\'e that feeblemindedness was not a 

 unit character but showed continuity 

 with the normal population. Still later 

 Karl Pearson published in the same 

 series a lecture* reviewing the whole 

 situation, and ]3ointing out the need for 

 some accurate measurement of the 

 higher grades of mental deficiency. 

 "That a real measure will be found^ 

 short of the experimental method of 

 testing actual success or failure in the 

 rough and tumble of life — I am con- 

 vinced," he concludes, "but I doubt 

 whellier it has been found at present 

 and its discovery will not be expedited 

 by any scientific dogma that asserts all 

 mental defect is of one kind, and is due 

 to the absence of a determiner, a lack 

 which the feebleminded share with our 

 ape-like ancestors."' 



^ Mendelism and the Prol)k'm of Mental Defect. I. A Criticism of Recent American Work, 

 by David Heron, D. vSc. Pp. 62, ])rice 2 s. net. London, Dulau and Company, 1913. 



* Eugenics Record Office Bulletin No. 11. Reply to the Criticism of Recent American Work 

 by Dr. Heron of the Cjallon Labf)ratory, by C. B. Davenport and A. J. Rosanoff. A Discussion 

 of the Methofls and Results of Dr. Heron's Criticiue, by C. B. Davenport; Mendelism and Neuro- 

 pathic Heredity, by A. J. RosanofT, M. D. Pp. 44, ])ricc 10 tents. Cold Sprin>^ Harbor, Long 

 Island, N. Y., February, 1914. 



'Mendelism and the Problem of Mental Defect. II. 'riic Continuity of Mental Defect, by 

 Karl Pearson, F. R. S., and Gustav A. Jaederholm, Pli. 1). i'rice 1 s. net. London, Dulau and 

 Company, 1914. 



" Mendelism and the Problem of Mental Defect . III. On the Graduated Character of Ment al 

 Defect and on the Need for Standardizing Judgnnnts a'- iu the Grade of Social Inefficiency Whicli 

 Shall Involve Segregation, by Karl Pearson, F. R. S. Pp- ^L price 2 s. net. London, Dulau 

 and Com])any, 1914. 



^ This refers to the suggestion of C. B. Davenjjort (see Popular Science Afonthly, January, 



a special race, sharjjly differentiated 

 from normal -minded folk," says Karl 

 Pearson. "There is every grade of 

 feeblemindedness . . . and as far as 

 mentality is concerned no .shaqj line 

 can be drawn across the population, 

 and those on one side of it treated as 

 normal and those on the other as 

 mentally defective," — a statement of 

 the case that I think Goddard and most 

 other students would accept. 



This fact of continuity has an im- 

 portant bearing on all work with the 

 feebleminded as a class. To the student 

 of heredity it is particularly important, 

 because most of the present-day studies 

 of heredity start with the asstimption 

 that each character inherited is a unit. 

 Can we speak of a unit character, when 

 it shades off im]jerccptibly into another 

 — can we call feeblemindedness a unit, 

 when no line can be drawn between it 

 and its supposed alternative or "allelo- 

 morph," a normal mind? 



THE UNIT CHAR.\CTER QUESTION 



This question has caused bitter disa- 

 greement among eugenists. The earlier 

 students of the subject assvimed that 

 it was a unit character and interpreted 

 their ]X'digrees in that light. The\' 

 called it a recessive trait, normal 

 mentality being dominant. From the 

 very beginning, psychologists had on 

 the whole refused to assent to this pro])- 

 osition. Goddard himself "confesses to 

 being one of those ]jsychologists who 

 find it hard to accept the idea that the 

 intelligence even acts like a unit char- 

 acter," although his own figures force 

 him to say that "there seems to be no 

 way to escape such a conclusion." But 



