NURTURE AND NATURE 3 I 



morally defective parentage. Can it be that these 

 home conditions keep the children in the streets, 

 and so relatively away from bad environment and 

 in relatively fresher air ? Whatever may be the 

 cause the Edinburgh statistics show that the effect 

 of home influence is not one-tenth that of heredity, 

 and what exists, if it is appreciable at all, is in the 

 opposite direction from what we should have antici- 

 pated. Intelligence is slightly associated with few 

 people per room and with a good economic condition 

 in the home for boys and girls, though for boys it 

 is scarcely appreciable ; it is also associated for girls 

 very slightly with good physical and moral condition 

 in the parents, but for boys we get better intelligence 

 in the children associated with bad physical and 

 moral condition in the parents. 



Glands and hearing tell the same tale. There Is 

 only a slight connection between the presence of 

 swollen glands or bad hearing and bad environ- 

 mental conditions. All the coefficients are small 

 and Irrregular, some scarcely appreciable, but in 

 most cases they are positive, I.e. better physique 

 goes with better environment, though it is but In a 

 weak degree \ 



Such a table as that on p. 30, indicating in many 

 directions the relative insignificance of nurture in 



^ Heredity as before plays far the larger part. The measure of 

 the inheritance of eyesight is equal to that found for other physical 

 characters and the same is true of intelligence (•49). Recent work of 

 the Laboratory (^r///j-/^ Medical Jouriidl^ July, 1909: see Appendix 

 to this Lecture) shows that environmental conditions can hardly be 

 the chief source of eye-disease. The correlations are low and more 

 often negative than in the case of ear-disease. 



