34 SOME RECENT MISINTI- KPRETATIONS OF THE 



by environment is tin- actual rani^r of environments in which he 

 finds the organism >ulistini,'. and he asks whether when environ- 

 ment IN varied within this range the characters of the organism are 

 changed to the same extent as they are by such variations as occur 

 in the ancestry of existing members of the race. In other words he 

 measures and compares variations in the individual produced by 

 varying existing environment and by varying ancestry among possible 

 existing types. The biometrician does not stay to discuss what would 

 happen if you kept your human being under a pressure of fire 

 atmospheres or at a temperature of 100 Fahr. The biometrician 

 contents himself with a practical problem; he asks how changes 

 which are within" the range of practical politics the replacement of 

 "back-to-back" houses by "through" houses, the abolition of cess- 

 pools, the diminution of overcrowding, the provision of better lighting 

 or ventilation and so forth would improve the child as compared 

 with selecting parentage by sound health, efficient mentality and good 

 habits. Such is the problem of environment and heredity that the 

 biometrician has in mind, and such is the problem that he answers 

 when he says that the influence of nature on the average is five to 

 ten times as important as that of nurture. We assert that given the 

 existing range of variation in possible parents and given the existing 

 range of variation in possible environments, the association between 

 variation in the offspring and variation in the parent is far more 

 intense than the association between variation in the offspring and 

 variation in the environment. We obtain this result by proving that 

 the correlations in the two cases are of a wholly different order. In 

 other words the relationship between parent and offspring is far closer to 

 a causal bond than' the relationship between environment and offspring. 

 Biometricians have, I hold, been perfectly consistent in what they 

 have done ; they have not used environment or nurture in any vague 

 sense ; they have taken the range of environment which occurs within 

 practical experience, they have dealt with variations of nurture subject 

 to municipal or state control ; they have considered the time children 

 spend in the school, at home, on the streets; they have dealt with 

 occupations, wages and ages of parents; they have considered in 

 short all the social, industrial and economic conditions of the environ- 

 ment of the child of which they could procure data, or which admitted 

 of measurement and record, and they have shown that the variations 

 in these factors of nurture are of relatively small importance compared 

 with the results of variation in the physique, the mentality and the 



