114 THE TREND OF THE RACE 
traced in more than 1 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 
