THE STATUS OF MAN. 265 



will be. It would be very remarkable if they finally developed 

 in the same way, became pure for the same type. Two groups 

 of people may originally be of common descent and keep from 

 mixing because they live in different parts of the world. Each 

 group will tend towards its own type and as each assimilates 

 different smaller groups of original occupants or of immigrants 

 there is enough chance for an eventual difference in type. 

 (Canadians- Australians) . 



If groups of people living in close proximity, making up one 

 nation, are sufficiently different to make the genotypic differ- 

 ence apparent, they tend to remain separate because of an 

 aversion to mixed marriages which keeps these below the 

 maximum. This maximum of the percentage of mixed mar- 

 riages of the total number of marriages consistent with specific 

 difference must in man, where the rate of reproduction and the 

 infant mortality are so low, be necessarily very low. We see 

 such an aversion to mixed marriages keeping species separate 

 in cases where the genotype of the two species is very different, 

 Negroes and whites, Chinese and Malay. Occasionally such dif- 

 ferences are accentuated by differences of religion or language. 



Next we have to consider the case in which originally non- 

 genetic differences are strong enough to. keep groups of people 

 separate, even where they occur intermingled. In man, with 

 the importance of language and of the printed record, the in- 

 fluence of outstanding individuals becomes important out of 

 all proportion to their hereditary power, and quite indepen- 

 dently from this. Apart from this influence of men upon other 

 men, we have a circumstance which has great influence in 

 man: the transmission from parents to off-spring of non-genetic 

 developmental-factors. In the first place, we for the first time, 

 meet here imitation and tradition as influences, which shape 

 the development of man to an incomparatively greater extent 

 than in any other animal. Imitation and tradition makes chil- 

 dren very much more like their parents than an inheritance of 

 genetic factors alone would make them, and more unlike mem- 

 bers of a foreign species. 



