3i6 STATISTICAL STUDY OF INHERITANCE 



While Gallon's clearest results were obtained from data as 

 to stature, the general conclusion was confirmed in regard to 

 eye-colour, artistic faculty, and other qualities. There seems 

 no reason to doubt the general occurrence of regression towards 

 mediocrity, though it is doubtless modified in regard to char- 

 acters which are subject to keen selection, either natural or 

 sexual. 



" The law of regression tells heavily against the full hereditary 

 transmission of any gift. Only a few out of many children 

 would be likely to differ from mediocrity so widely as their 

 mid-parent, and still fewer would differ as widely as the more 

 exceptional of the two parents. The more bountifully a parent 

 is gifted by nature, the more rare will be his good fortune if he 

 begets a son who is as richly endowed as himself, and still more 

 so if he has a son who is endowed yet more largely. But the 

 law is even-handed ; it levies an equal succession-tax on the 

 transmission of badness as of goodness. If it discourages the 

 extravagant hopes of a gifted parent that his children will 

 inherit all his powers, it no less discountenances extravagant 

 fears that they will inherit all his weakness and disease " (p. io6). 



" It must be clearly understood that there is nothing in these 

 statements to invalidate the general doctrine that the children of 

 a gifted pair are much more likely to be gifted than the children 

 of a mediocre pair. They merely express the fact that the 

 ablest of aU the children of a few gifted pairs is not likely to be 

 as gifted as the ablest of all the children of a very great many 

 mediocre pairs" (p. io6). 



Nor must the fact of regression be supposed to affect the 

 general value of a good stock or the general disadvantage of 

 a bad one. Two gifted members of a poor stock may be person- 

 ally equivalent to two ordinary members of a good stock, but 

 " the children of the former will tend to regress ; those of the 

 latter will not " (p. 198). 



Let us give a concrete illustration from Prof. Karl Pearson's 



1 



