GENETICS OF THE HUMAN MIND 



C. C. HURST, Sc.D., Ph.D. 



Cambridge, England 



Sixty-three years have passed since the appearance of Sir Francis Gal- 

 ton's pioneer work on Hereditary Genius. In that classic, Galton shows in 

 numerous and diverse cases that natural ability and high mental capacities 

 have in all probability been derived from parents and ancestors. Since 

 then, Galton's conclusions have been confirmed and highly developed sta- 

 tistically by Professor Karl Pearson (1919) and others. In 1906 a remark- 

 able survey of Mental and Moral Heredity in Royalty, carried out 

 on Galtonian lines, was published by Dr. F. Adams Woods, which, dealing 

 with the whole adult issue of the leading Royal families of Europe through 

 several centuries, leaves no doubt that mental ability of different grades is 

 inherited and transmitted to descendants in an "alternative" manner. 

 Thus the accumulation of statistical evidence indicates that the influence of 

 heredity is of primary and paramount importance in the determination of 

 the human mind. Mankind's chief distinction from the other Primates and 

 the rest of the Mammals, lies in his more recently developed conceptual mind 

 or intellect, the first traces of which date back to the Cantalian Eoliths of the 

 early Pliocene about ten million years ago, long before the appearance of 

 the genus Homo and the modern species Homo sapiens. Since the dawn of 

 civilisation about ten thousand years ago, the progress of the human race 

 has in the main depended on the development of the intellectual capacities 

 and in studying the genetics of the human mind it should be our first concern 

 to investigate the genetics of intellect. 



The statistical evidence of Galton, Pearson and Woods does not indicate 

 the genetical mechanism whereby intellectual abilities are inherited and 

 transmitted from generation to generation and at that early date both Pear- 

 son and Woods disclaimed a Mendelian interpretation of the evidence . Since 

 then considerable progress has been made and Mendel's experiments have 

 provided a key to the mechanism of heredity, segregation and "alternative" 

 inheritance, while recent genetical experiments have with certainty demon- 

 strated that the physical basis of this mechanism in plants and animals is 

 found in the chromosomes and genes present in the nucleus of every living 



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