338 The Study of Animal Life part iv 



work has been in great part an application of the statistical 

 law of Frequency of Error to the records accumulated. 



The main problem of his work is concerned with the 

 strange regularity observed in the peculiarities of great 

 populations throughout a series of generations. " The 

 large do not always beget the large, nor the small the 

 small ; but yet the observed proportion between the large 

 and the small, in each degree of size and in every quality 

 hardly varies from one generation to another." A specific 

 average is sustained. This is not because each individual 

 leaves his like behind him, for this is not the case. It is 

 rather due to the fact of a regular regression or deviation 

 which brings the offspring of extraordinary parents in a 

 definite ratio nearer the average of the stock. 



" However paradoxical it may appear at first sight, it is 

 theoretically a necessary fact, and one that is clearly con- 

 firmed by observation, that the stature of the adult offspring 

 must on the whole be more mediocre than the stature of 

 their parents — that is to say, more near to the median 

 stature of the general population. Each peculiarity of a 

 man is shared by his kinsmen, but on an average in a less 

 degree. It is reduced to a definite fraction of its amount, 

 quite independently of what its amount might be. The 

 fraction differs in different orders of kinship, becoming 

 smaller as they are more remote." 



Yet it must not be supposed that the value of a good stock 

 is under-estimated by Galton, for he shows how the offspring 

 of two ordinary members of a gifted stock will not regress 

 like the offspring of a couple equal in gifts to the former, 

 but belonging to a poorer stock, above the average of which 

 they have risen. 



Yet the fact of regression tells against the full transmission 

 of any signal talent. Children are not likely to differ from 

 mediocrity so widely as their parents. " The more bounti- 

 fully 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 

 more largely." But " The law is even-handed ; it levies an 

 equal succession -tax on the transmission of badness as of 



