ii4 THE TREND OF THE RACE 



traced in more than i per cent of the cases. "No doubt," says 

 Ellis, "this result is below the truth, . . . the insanity of the 

 parents must sometimes have escaped the biographer's notice. 

 But even if we double the percentage to escape this source of 

 error, the proportion still remains insignificant." 



A few years ago without being aware of the existence of Ellis' 

 work, I suggested to one of my students, Mr. C. A. James, that 

 he ascertain the percentage of insanity in chosen lists of great 

 men. Taking the men from Galton's Hereditary Genius and a few 

 shorter lists, it was found that pronounced cases of insanity 

 occurred in less than 2 per cent. Cases of slight neuropathic 

 disorders were not included because it was the aim to employ 

 much the same standards for judging people insane as are em- 

 ployed in collecting statistics of insanity in the general popula- 

 tion. Over one-fifth per cent of the population in the United 

 States are in hospitals for the insane according to the census for 

 1910. About one-third of this number is discharged every year, 

 many of whom soon find their way back again, and since many 

 others are cared for outside of hospitals, we may estimate conserv- 

 atively in the light of statistics from other countries that at any 

 given time one-third per-cent to one-half per cent of the popula- 

 tion is actually insane to a degree that would warrant custodial 

 care. When we limit our enquiry to the percentage of insane cases 

 among people within the age limits in which a reputation may be 

 gained for intellectual eminence, the percentage of insanity would 

 naturally become several times greater. Then, if we further 

 consider the number within these age limits who will develop 

 insanity sometime during their lives we will obtain a much larger 

 ratio still, but one which may be compared with the ratio of 

 insanity found to occur among those who have become noted 

 for their intellectual ability. What data we have on the subject 

 indicates that insanity is rather less frequent among the intellec- 

 tuals than the people at large. Certainly there is a much higher 

 correlation between insanity and feeble-mindedness than there is 

 between insanity and genius, unless we define genius in such a 

 way as to include only those great men who are one-sided or 



