A STUDY OF BRITISH GENIUS. 



213 



account, the fertility is greatly pulled down, but still remains well up to 

 the average. This normal average is thus attained by a conjunction 

 of an abnormal proportion of sterile marriages, together with an ab- 

 normally high proportion of children among the fertile marriages. 



There would appear to be a considerable resemblance between the 

 fertility of genius families and of insane families. We have seen 

 previously that our eminent British persons belonged to families of 

 probably more than average fertility; we now see that they themselves 

 produced families of probably not more than average size, owing to a 

 greater prevalence of sterility. In France, Ball and Regis, confirmed 

 by Marandon de Montyel, appear to have found reason for a similar 

 conclusion regarding the insane. They state that natality is greater 

 among the ascendants of the insane than in normal families, but after- 

 wards it is the same as in normal families, while they also note the 

 prevalence of sterility in the families of the insane.* The question, 

 however, needs further investigation. 



With regard to the distribution of families of different sizes, the 

 results, as compared with the figures already given, are as follows: 



Size of Family.. . 

 Normal Families. 



Genius-producing Families. 

 Families of Men of Genius.. 



6.3 



6.9 



4.7 



Size of Family. . . 

 Normal Families. 



Genius-producing Families. 

 Families of Men of Genius. . 



Allowing for certain irregularities due to the insufficient number 

 of cases, the interesting point that emerges is the return towards the 

 proportions that prevail in normal families; it \vill be seen that in all 

 but a few cases the families of men of genius differ from genius-pro- 

 ducing families by approximating to normal families. It must be re- 

 membered that in neither of our groups are the data absolutely per- 

 fect, but as they stand they confirm the conclusion already suggested 

 that men of genius belong to families in which there is a high birth- 

 rate, a flaring up of procreative activity, which in the men of genius 

 themselves subsides towards normal proportions. The slightly larger 

 average size of the families of men of genius as compared with normal 

 families is merely due to the presence of a few families of excessively 

 large size. 



* See, for a summary of these results, Toulouse, 'Les Causes de la Folie,' p. 91; 

 1896. 



