44 SOME RECENT MISINTERPRETATIONS OF THE 



isolated aspects of the latter. As a matter of fact it is quite beyond 

 our power at present to sum up the full effect of environment upon 

 the individual and compare it with the full effect of heredity. \\V 

 are, therefore, justified in saying that we neither know in particular 

 cases how far the environment can produce any effect, nor can we 

 make any definite statement as to the comparative strength of ' nature ' 

 and 'nurture.'" 



Now this is the doctrine passed by the Editors of the Eugenics 

 Review, a society, which masquerades under the name of Francis 

 Galton 1 , and it is passed, because the editorial committee of that 

 society does not grasp the meaning of multiple correlation! In the 

 first place, of course, a single correlation coefficient does not provide 

 a full measure of the strength of heredity. In the table cited the 

 coefficients are those for one parent or for one brother or sister. Each 

 relative and those for independent stocks are either non-correlated 

 or inter-correlated very slightly provides such a coefficient, and 

 further each character in such relatives may be correlated with the 

 character under discussion in the person in question. In the next 

 place the environment factors do not consist of "some one isolated 

 aspect of environment." All these factors or aspects are closely 

 interlinked, and this was a fact well-known to the workers in the 

 Galton Laboratory. The real interpretation of such a difference as -50 

 and -03 in the average values of single coefficients can only be appre- 

 ciated by those who are conversant with the theory of multiple 

 correlation, and it is quite clear that those who profess to guide the 

 public in this very difficult problem which is essentially a scientific 

 problem lack any adequate knowledge of the sole instrument by 

 which any legitimate conclusion can be drawn. 



The writer quoted appears to be wholly ignorant of the nature of 

 multiple correlation in the first place and in the second entirely to 

 overlook the very high correlations which exist between environmental 

 factors. Bad wages, bad habits, bad housing, uncleanliness, insanitary 

 surroundings, crowded rooms, danger of infection, &c., &c. are all 

 closely associated together, and while the order of correlation between 

 environmental and physical characters is low, that between individual 

 environmental factors is in our experience very high. Thus the 

 problem of heredity and environment is essentially the same as the 

 problem of multiple correlation. 



1 If there was one point on which Francis Galton felt strongly and wrote it was 

 on this point of the relatively great intensity of "nature" as compared with "nurture." 



