NURTURE AND NATURE ' 21 



Here the results are very regular and practically 

 the same for height and weight. There is a certain 

 very slight association between the unhealthy trade 

 of a father, as measured by the mortality rate, and 

 inferior physique in his children in the worst school 

 group, but it becomes practically nil in the better 

 school groups. We must again notice the low value 

 of the correlation coefficient when we compare it 

 with the value found for the correlation between 

 height of father and son. And in this case also 

 I must point out that we do not know how much 

 of this apparent association is due indirectly to 

 heredity, and to the probable fact that on the whole 

 weaklings are driven into less desirable occupations. 

 A man who is physically unfit has to work for any 

 employer who will take him, and we shall probably 

 frequently find him doing casual labour or working 

 in a factory where little bodily strength is required. 

 Here again we need the average height and weight 

 of the fathers of all these sons to see whether fathers 

 in a trade with a low mortality rate are taller and 

 heavier than fathers in a trade with a high mortality 

 rate. Is the casual labourer with a mortality rate of 

 1 8 per thousand lighter and shorter than the carter 

 with a mortality rate of 8 per thousand ? the factory 

 hand with a mortality rate of 1 3 per thousand than 

 the blacksmith with a mortality rate of 7 per thou- 

 sand? If so, children of the casual labourer or the 

 factory hand will be lighter and shorter than the 

 children of the carter or blacksmith, quite apart from 

 any direct influence of unhealthy employment. 



In the Appendix to the Report of the Royal 



