NURTURE AND NATURE II 



We must next compare the influence of the employment of the 

 mother on the physique of her son with the hereditary influence of 

 the actual height of the mother on the height of her son. This 

 hereditary influence is given in Table I for the sake of comparison. 

 The effect of inheritance of stature of mother and son is measured by 

 the coefficient -49. The coefficients for eye-colour for the parental, 

 grandparental, and great grandparental relationships are also given, 

 and it will be noticed that the only value at all comparable with the 

 environmental values is that found for great grandparents, which is 

 about equal to that found for the effect of mothers' employment on 

 sons' height in Glasgow, but distinctly higher than the other correlation 

 coefficients. We cannot help being struck by the comparative unim- 

 portance of, at any rate, one environmental factor as compared with 

 the heredity factor. 



We will add one further remark on the differences we have found 

 in the correlations between employment of the mother and height of 

 her sons in Glasgow. In Glasgow the values found range from ! 

 to -2. At present we have no final explanation beyond heterogeneity 

 for this result. But we would mention a fact noted by Dr Tocher in 

 a paper on the pigmentation survey of Scotland, published in Biometrika, 

 vol. vi, pp. 129 235. In that paper Dr Tocher calls attention to the 

 large foreign element in Glasgow as judged by the names of the children 

 and confirmed by their hair and eye-colour. There are a large number 

 of Jews, especially in Groups B and C, and a fairly large proportion 

 of Irish in the schools in Group D. Can mixture of races account for 

 the higher correlations in some of the Glasgow groups 1 ? 



Future investigations will show whether the influence of the 

 mother's employment on the height of her sons is greater than (as 

 apparently in Glasgow) or less than (as apparently in Edinburgh) the 

 influence of her employment on the weight, and whether the influence 

 of employment on height is represented by the higher or lower 

 correlation coefficient, by -2 or by -i. At present we must content 

 ourselves with saying that the connection between the employment 

 of the mother and the weight of her sons is about -12, and that the 

 connection between the employment of the mother and the height of 

 her sons is between ! and -2. Taking into consideration the result 



1 If we compare the mean height and weight of the Edinburgh boys with those 

 of boys in the different school groups at Glasgow, we find that they lie between the 

 Glasgow groups A and B, just where the correlation coefficients fall. Thus the 

 Edinburgh and Glasgow values may not be really contradictory. 



