56 SOME RECENT MISINTERPRETATIONS OF THE 



Now although it seems proper to exclude these probably hereditary 

 factors from an examination of true environmental factors it is worth 

 while to notice the extent to which the indirect parental and physical 

 environmental factors depend on the direct parental factors. The 

 fact is that parents of bad habits and poor health by a process of 

 selection gravitate to the worse type of dwelling. When we remember 

 that infant mortality and health of mother have a correlation of -30 in 

 Blackburn, and delicacy of infant and health of mother a correlation 

 of -41 in Bradford, while health of offspring and health of either parent 

 have a correlation of about -50 in the professional classes, we realise 

 how largely health is a matter of nature, not of nurture. In confirma- 

 tion of this consider the following results : 



TABLE X. 



Association of Health of Mother with Physical Factors. 

 Bradford and Blackburn. 



Bradford Blackburn 

 Health of mother and overcrowding ... ... ... -25* -01 



,, ,, ,, type of house ... ... ... -19 



,, number of rooms ... ... -13 -20 



,, sanitation ... ... ... --05 



,, rent ... -26 -12 



Mean correlation ... ... '14 



* Measured for Bradford by pence per person spent on rent. 



It would thus appear that the association of bad physical environ- 

 ment with mother's bad health is not a third as intense as the 

 association of mother's health with that of her offspring. Even then 

 it would be wrong to assert that the bad health of the mother flows 

 from the environment. The unhealthy woman fails to find a healthy 

 normal husband, she is less often employed and thus the family income 

 being lower, there is more overcrowding, and the home is made in a 

 cheaper and inferior type of house. The fact that in Blackburn the 

 correlation between mother's health and insufficiency of food in the 

 family is -47 and between father's health and insufficiency of food 

 is -40, indicates how greatly health in parents affects the economic 

 condition of the family. It may be doubted whether physical 

 environment would show any sensible relation to mother's health 

 were the values corrected for income of family. 



On the other hand as the next table will show the direct parental 

 environmental factors summed up in habits of mother and cleanliness 



