THE INHERITANCE OF ABILITY 



A study of the role of heredity in Terman's case histories of forty-one superior 



children 



Doris Davidson 



University of Pittsburgh, Pittsburgh, Pa. 



IN A RECENT book, Professor Lewis 

 M. Terman of Stanford Univer- 

 sity has presented case studies of 

 41 children who were found by mental 

 tests to be exceptionally intelligent.^ 

 It seemed worth while to extract the 

 data he gives regarding their ancestry, 

 in order to bring this feature of the 

 story into relief. 



Concerning the parents or the hered- 

 itary strain of six of these children, 

 there are no data given. What we 

 know about the parents of the remain- 

 ing thirty-five children, as is shown by 

 education, occupation, and family con- 

 nection, would seem to indicate that 

 the parents of superior children are, 

 in almost all cases, themselves superior. 

 In many cases full information about 

 the parents and relatives is not ob- 

 tainable but a study of what we have 

 reveals the following interesting facts: 



In twenty-two cases the occupation 

 of the father is given. Of the twenty- 

 two, eighteen are professional men. 



In seventeen cases one of the parents 

 is a college graduate. In several 

 other instances the parents are spoken 

 of as "well-educated," "of superior 

 ability," etc., but no indication is 

 given of how far they went in school. 



Seven of the children have both 

 father and mother who are college 

 graduates. 



The parents of four have only com- 

 mon school education. In three of 

 these cases some relatives are men- 

 tioned as being superior. 



Only in two cases is it said that there 

 are no superior relatives on either the 

 father's or the mother's side. In 

 both these families there are other re- 

 markably bright children beside those 

 tested so it would appear that there 



must be some superiority in the stock 

 from which they came. 



Eleven of the children have unusu- 

 ally fortunate heredity. In many cases 

 the superiority has been noted for 

 several generations and is widely dis- 

 tributed among various branches of 

 the family. The superiority is usually 

 general in both child and parents but 

 where it is focussed upon a special 

 subject, the particular interest of the 

 child is almost as likely to be difTerent 

 from that of his parents or relatives 

 as it is to be like it. At least one parent 

 of ten, of the eleven children, who 

 ranked at 150 or higher was a college 

 graduate. 



A brief record of the heredity of 

 each of the "Forty-one Superior Child- 

 ren" follows:^ 



No. 1, Score 166. Father a profes- 

 sional man. Mother a university grad- 

 uate and former teacher. Maternal 

 grandmother a university graduate and 

 school principal with marked mathe- 

 matical ability, which is also shown by 

 the child. 



No. 2. No record of his heredity 

 given. 



No. 3, Score 150. Father superin- 

 tendent of schools. 



No. 4, Score 153. Father a college 

 professor and journalist. Mother a 

 college graduate of unusual ability and 

 musical talent. Several relatives of 

 superior ability. 



No. 5, Score 147. A sister of No. 4. 



No. 6, Score 144. Father of superior 

 ability. Mother secretary for a large 

 business firm. 



No. 7, Score 146. Father, French. 

 Mother, American. Musical family. 

 Great grand uncle was Meyerbeer the 

 French composer. Another uncle is a 



The Intelligence of School Children, chap. xi. Boston, Houghton 



The normal intelligence, or 



' Terman, Lewis M 

 Mifflin Co., 1919. 



^ The rank of "score" mentioned is the intelligence quotient, 

 average at a given chronological age, is taken as 100. 



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