314 



The Journal of Heredity 



good. By tlie percentile method of 

 scoring she is found to rank among the 

 best ten or twenty of one hundred 

 children of the same age, for the \K\.r- 

 ticular tests under discussion. Such 

 caj)acity involves nothing spectacular, 

 and is. therefore, of the more value in 

 demonstration of the minuteness with 

 which native traits may be parcelled 

 out. The especial point of interest is 

 the revelation of this capacity in the 

 very early play of the child. It is 

 ])robal)le that Virginia inherits her skill 

 in spatial orientation from the paternal 

 side, as her relatives on her mother's 

 side are very deficient in this capacity. 

 At nine years \'irginia is absurdly more 

 apt at form-boards than her maternal 

 aunts. She is also much readier than 

 her small brother and sister. 



UXIDEXTRALITV 



In studying unidextrality and its 

 complications. I have had recourse to 

 comj)arative measurements of the right 

 and left arms, using Dr. Jones' brachio- 

 meter. which has been devised for just 

 this purpose. X'irginia shows greater 

 excess of ditiference in length between 

 the right and left arm than does either 

 of the other children. This I antici- 

 pated, since, according to a theory upon 

 which 1 am at present working, skill in 

 handling spatial relationships is. in part 

 at least, a function of a high degree of 

 unidextrality. 



Case IV is that of a very superior 



child. John 11.. who, at four years eight 

 months, has a mental age of over six 

 years. But his record in rei)eating 

 digits after the examiner in both nat- 

 ural and reversed order outstrips his 

 other reactions, since his performance 

 is that of a ten-year-old child. This 

 capacity is shared by a brother, a year 

 older, and is exhibited also by adult 

 members of the family. 



Case V. — Paul S., at eight years, pos- 

 sesses a mental age of ten; his vocabu- 

 lary record, however, is that of the 

 twelve-year-old child. His gift in this 

 direction was evident at two years, at 

 which time a list of the words used 

 within a prescribed time totaled 711, 

 with an estimate of 750 as his actual 

 vocabulary. This is a very remarkable 

 record, as shown by a comparison with 

 other vocabularies reported for children 

 of the same age. Paul's environment is 

 undoubtedly a very favorable one for 

 development of this gift, but only native 

 capacity can explain the fact that his 

 two-year record surpasses that of other 

 children in the same family. 



The instances cited above are very 

 simple ones, and no doubt could be 

 easily duplicated. They are. for that 

 very reason, perhaps, more convincing 

 in their bearing upon the all-pervasive 

 quality of mental heredity. Certainly, 

 most psychologists are keenly alive to 

 the big problems involved in mental in- 

 heritance and anxious to deteriuine the 

 limits set to training by mental capacity. 



"Psychobiology" 

 A New Publication of Interest to Biologists 



Psyclwbiology will include research 

 on problems which involve mental or 

 conscious factors as details in the total 

 fimctioning of the organism, as well as 

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 ological imjxjrtance are involved in the 

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 will be included in so far as they fall 

 within the fieUl of psychol)iology. 



The journal is edited by Professor 

 Knight Dunlap of Johns Hopkins 

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 the United States is $5.00 a volume. 

 Williams and Wilkins Company. 2419- 

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