GENETICS OF HUMAN MIND 415 



Space will not allow the publication of full details here, but complete 

 tables of the individuals of the 406 families will be found in Hurst (1932 A), 

 genetical proofs of the formula in Hurst (1934), and it is hoped that it will 

 be possible to publish a large number of the case studies in the form of a 

 book. 



EUGENICS 



From the point of view of Eugenics, the novel and manifold implications 

 of the genetical formula are important and far-reaching. The presence and 

 frequency of the dominant N gene in a population, giving rise automatically 

 to an excessive number of mediocre individuals of grade 5, no matter how 

 many increaser genes for intellect they may be carrying and with no prospect 

 of their coming to expression except by a loss or mutation of N genes, raises 

 a vital eugenic problem. The more NN and Nn individuals in a population 

 the higher the frequency of mediocre intelligence and the lower the Intelli- 

 gence Index (i.e. , the percentage of high grades) . The lower the Intelligence 

 Index the less progressive the nation and the less likelihood of the preserva- 

 tion of advanced civilisation. The lower average of intellect in certain back- 

 ward races may be due to an excess of dominant N genes in the population. 

 It may be that here we have an explanation of the sudden fall of Greece and 

 Rome and other dominant Empires and Civilisations owing to the introduc- 

 tion and rapid spread of N genes through intermarriages with mediocre 

 races. For this reason the reproduction of families with nn parents should 

 be encouraged in every possible way, but even here safeguards will be neces- 

 sary since both low and high grades are associated with the nn pair of genes 

 and it may be expected that in certain families genius will be associated with 

 decadent and degenerate members with a low grade of intelligence. For- 

 tunately the high and low grades of intellect, though frequently associated 

 are not inseparable, and it is possible by selection to decrease the low grades 

 and increase the high grades by encouraging the reproduction of large 

 families by parents of grade 6 and over. 



Professor Terman's (1930) studies of a thousand gifted children show 

 clearly that children of grade 7 and over, are in general and on the whole, 

 superior in the more desirable qualities of temperament, health and physique 

 to the average child of grade 5. 



In another place (1934), I have suggested a scheme of Family Bounties 

 in which high grade parents of grades 6 and over would receive Bounties for 

 the education and maintenance of each of their high grade children. As a 

 practical scheme of positive eugenics, the effects of the Family Bounties 

 would soon be evident and in the course of a generation they would be in- 



