FEEBLE-MINDEDNESS 281) 



either that they represent a primitive, animal-like eonditiuu 

 of the human race, which has survived down to the present 

 time, or that they represent a retrogressive (loss) variation. 

 The manner of inheritance of the condition is of iiitiTesl in 

 connection with this question, for evolution by loss usually 

 results in the production of recessive variati(jns. 



Goddard's evidence indicates that feeble-mindednrss i> a 

 recessive unit-character. In his family records one hundred 

 and forty-four matings of feeble-minded inter se have j)ro- 

 duced seven hundred and forty-nine children of whom four 

 hundred and eighty-two are of ascertained mentality. Of 

 these, all but six are recorded as feeble-minded. These few- 

 exceptions to theoretical expectation might be explained as 

 being of ancestry other than that assigned. A case reported 

 from an Ohio institution illustrates the point well. "In a 

 white family, the father and mother are both feeble-minded. 

 They have twelve children, all feeble-minded but two. These 

 two are normal (as regards intelligence) but they are colored." 



TABLE 37 

 Data on the Inheritance of Feeble-Mindedness 



Children 

 Mating F-M N 



F X F 476 6 



F X N 193 144 (N heterozygous ?). Some families tabulated 



here belong above, probably. 



F X N . . 68 (N homozygous ?). 



NXN 39 83 (Both heterozygous ?). Some belong above, prol>- 



ably. 



NXN . . 116 (One or both homozygous ?). 



The data of Goddard indicate clearly that feeble-mindedness 

 is inherited as a recessive Mendelian character, but one which 

 like albinism may occur in many different grades, the higluT 

 grades probably tending to dominate. The feeblr-niindt-d 

 are frequently deficient in physical strength and vigor. II o w- 

 ever, many of them seem to possess unusually good physic lue. 

 Goddard compares them to savages with strong bodies but 

 childish minds. The high-grade feeble-minded, kncnvn as 

 " morons," with mentality of eleven or twelve years, are 



