TEADITION AND HEREDITY 469 



and further what innate differences may be supposed to underlie 

 these apparent differences. The results of inquiries made to test 

 the relative inteUigence of children of parents of different social 

 status are fairly uniform. Bridges and Coles, for example, found as 

 the result of such an investigation that ' there was very considera- 

 ble dependence of intelligence upon "sociological conditions'"; 

 they go on to say that ' when children are classified according to 

 the occupations of their fathers, a striking correlation is shown 

 between intelligence quotient and occupation group. Hence if 

 mental age rather than chronological age were used to determine 

 the time for beginning school, the children of the professional 

 group, for example, would begin school two years earlier than the 

 children of the unskilled labour group ; for the former mature 

 intellectually much earUer than the latter.' ^ The interpretation 

 of such observations bristles with dijBficulties. It is not clear what 

 relation earlier maturity bears to adult intelligence. Though the 

 direct effect of the environment is probably negligible, the possi- 

 bihty that tradition may influence the results is certainly not 

 shut out. Indeed, the fact that the correlation is higher for boys 

 than for girls suggests that tradition does come in. Nevertheless, 

 a consideration of these results suggests that the whole explana- 

 tion cannot be found in tradition and that we have here a sign of 

 some superiority of intelligence in the children of parents of 

 a higher social status. More than that cannot be said. 



18. Let us approach the question in another way. Can we dis- 

 cover any characteristics distinctive of those who succeed in modem 

 society, who rise, as it is called, from the ranks of the wage- 

 earning classes, and, if we can, what these characters are and how 

 far we must assume the existence of innate differences to account 

 for them ? We may think of the upper social classes in England 

 to-day as faUing roughly into three divisions— the professional 

 and the business classes and those whose fathers, grandfathers, or 

 more remote ancestors came into possession of property by one 

 means or another. In the case of a small proportion of the latter 

 class, the position was won under conditions which differ more 

 or less profoundly from these ruling to-day. This section is 



» Bridges and Coles, Psychological Review, vol. xxiv, p. 29. These nutliora do 

 not commit themselves to any view with regard to the interpretation of tlioir 

 resultfi— a fact which commends the investigation to students A these matters as 

 indicating that the investigation was not undertaken with any hias (a condition 

 of things unfortunately not common in studies of this problem). 



