CORRELATION 



99 



In the following table there are set down the corre- 

 lation coefficients for stature in the case of seven pairs 

 of relations, as obtained from actual data of a similar 

 character to that already given by way of illustration. 



TABLE V. (FROM PEARSON). 



CORRELATION COEFFICIENTS FOR HUMAN STATURE. 



Father and son 

 Father and daughter 

 Mother and son 

 Mother and daughter 

 Brother and brother 

 Sister and sister 

 Brother and sister 



0-514 

 0-510 

 0-494 

 0-507 

 0-511 

 0-537 

 Q'553 



Of the above, the first four values, representing 

 correlation between parents and children, are seriously 

 affected by the fact that the statistics from which they 

 are derived show the existence of a marked correlation 

 between husbands and wives in point of stature, 

 amounting, indeed, to as much as 0-28 the result 

 of what is technically described as selective mating. 

 In the absence of such a relation between the statures of 

 the parents, the correlation between parent and child 

 might be expected to be distinctly less than that 

 between pairs of brothers or sisters. 



The term correlation replaces to some extent the 

 older term regression employed by Galton. When 

 speaking of regression the facts already described are 

 regarded from a slightly different point of view. It 

 is sometimes found convenient to speak of the regres- 

 sion of the mean stature of an array of sons toward 

 the mean of the general population, instead of speaking 



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