Febkuakt 4, 1910] 



SCIENCE 



173 



that two groups were the same in their 

 average mental ability, but that one group 

 showed little variation, all of its members 

 being miich alike and of nearly the average 

 intelligence, while the other group showed 

 great variability, ranging between the ex- 

 tremes of idiocy and genius. It is evident 

 that the two groups, though equal on the 

 average, would be very unequal in dealing 

 with a situation which demanded great 

 mental ability. One master mind could 

 supply ideas for the guidance of the group, 

 and his value would far outweigh the load 

 of simpletons which the group must carry. 



If groups of men differ in average intel- 

 ligence, this difference would have an influ- 

 ence on their effectiveness in mental work, 

 and so, no doubt, on their advance in civili- 

 zation. If groups differ in variability, this 

 would probably have a still greater influ- 

 ence. There is one respect in which groups 

 certainly do differ. They differ in size, 

 and size is an important consideration, even 

 from a purely biological point of view. 

 The more numerous the individuals born 

 into a group, the greater the absolute num- 

 ber of gifted individuals to be expected; 

 and in some respects it is the absolute 

 rather than the relative number of able 

 men that counts. Besides this, the larger 

 the group, the greater the chance of its pro- 

 ducing a truly effective genius, just as, in 

 the experiments of Burbank and other 

 breeders, a vast number of plants are 

 grown, in order to increase the chance of 

 sports occurring. 



One further consideration of this partly 

 biological, partly statistical, nature should 

 be brought forward before passing from 

 preliminary remarks to the consideration 

 of actual data. When the individuals 

 composing a group are measured or tested 

 in several traits, it is found that those who 

 rank high in one trait do not always rank 

 high in others. On the whole, there is 



more correspondence than opposition; an 

 individual who ranks well in one trait is 

 rather apt to rank well in others. The cor- 

 relation, as we say, is positive, but it is far 

 from perfect. The individuals most gifted 

 with ability in war are not altogether the 

 same individuals who are ablest in govern- 

 ment, or in art or literature, or in mechan- 

 ical invention. This fact is not only of 

 importance in reaching a just conception of 

 a group, but it should be considered in com- 

 paring dift'erent groups. The circum- 

 stances surrounding a group call for cer- 

 tain special abilities, and bring to the fore 

 the individuals possessing these abilities, 

 leaving in comparative obscurity those 

 gifted in other directions. Judging the 

 group largely by its prominent individuals, 

 we get the impression that the group is 

 gifted in certain lines, and deficient in 

 others. A nation whose circumstances call 

 for industrial expansion and the exploita- 

 tion of natural resources gives prominence 

 to those of its members who are successful 

 in these pursuits, and leaves in obscurity 

 many who have native capacity for military 

 leadership. Should war come to such a 

 community, time and bitter experience are 

 often necessary before the leadership can 

 be transferred from the previously eminent 

 men to those obscure and often despised 

 individuals who are capable of doing best 

 service in the new direction. This lack of 

 perfect correlation between various abilities 

 makes it difficult to judge of the capacity 

 of a group of men by casual observation; 

 and we must accordingly discount largely 

 the appearance of specialization of mental 

 traits in different peoples. 



All in all, the discovery of true inherent 

 differences between races and peoples is an 

 intricate task, and if we now turn to the 

 psychologist to conduct an examination of 

 different groups, and to inform us regard- 

 ing their mental differences, we must not 



