THE INHERITANCE OF MENTAL TEST ABILITIES 



ROSWELL H. JOHNSON 



University of Pittsburgh 



For twelve years the Committee on Exceptionally Able Youths of the 

 Civic Club of Allegheny County, Pennsylvania, has been assembling the 

 outstanding students of those about to graduate from high school for test- 

 ing. The students invited are those who are selected as having been highest 

 scholastically, in mental tests or in teachers' estimates. Those selected are 

 then given mental tests and sometimes scholastic tests of which some norms 

 are known. The number of students tested this past June was 188. 

 Awards were given to 64 of these as being in the highest 1/20 of the fresh- 

 man class of an average American college. 



The results of these Civic Club tests has given an opportunity to observe 

 whether the abilities thus discovered are wholly sporadic, are directly pro- 

 portional to educational advantages, or whether in some degree they "run 

 in families." 



At nearly every recent test there were two or more siblings or cousins of 

 previous awardees, although this would be much rarer if due to chance alone. 

 The graduates from the high schools of Pittsburgh alone were 2163 at this 

 commencement. However, where three or more siblings have graduated 

 it is uncommon for all three to receive an award. 



A report on these experiences was prepared in 1928 by Mary C. Warmbier, 

 in a thesis on file in the University of Pittsburgh Library entitled "The 

 Eugenic Aspect of the Pittsburgh Exceptionally Able Youth Movement" 

 who found twelve pairs of sibling awardees. She reported one remarkable 

 pedigree in which three interrelated families contributed cousin awardees 

 but all siblings in each family were not of awardee rank. Since then addi- 

 tional sibling pairs have been discovered. 



This year, for the first time, a third successive sibling in one family won 

 the award. Inquiry revealed that these three were the three eldest siblings 

 in the K family and that there was a fourth sibling just finishing the junior 

 year in high school who was estimated to be equally capable. A special 

 test consisting of the Detroit Advanced Intelligence Test Form V and the 

 Moss-Hunt-Omake Intelligence Test (First Revised Edition) was therefore 

 given simultaneously to the two parents and the four siblings. These two 



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