330 PROBLEMS OF HUMAN EVOLUTION 



do what is demanded of it, we equip it with some tool which 

 makes the work easy. There is, therefore, now no selection for 

 a make of hand that is a little superior in some way to the 

 ordinary ; the normal is good enough. 



Eljmina- i t i s impossible, however, to maintain that among civilised 

 stupidity peoples there is no elimination for stupidity. The extreme of 

 stupidity is idiocy, and idiots leave no descendants. Above this 

 extreme there must be a very low level of intellect which causes 

 a man to fail in life. He is not likely actually to starve through 

 want of brain, but he may be so badly off and may manage so 

 badly that most of his children may die in infancy. This will 

 depend very largely on whether the wife is as wanting as him- 

 self. When the wife has not the required minimum of wits it is 

 quite possible that the death of a large proportion of the children 

 will result even though the husband is better off in this respect. 

 But stupidity is mainly eliminated through sexual selection. A 

 workman does not want his home to be made miserable by a 

 feckless wife. Beauty may sometimes rob him of his reason, 

 but as a rule he will pick the shrewder (ceteris paribus) of two 

 sisters. I believe such selection must go on to a very consider- 

 able extent, but a combination of qualities is expected and so it 

 is difficult to discover what weight is attached to cleverness. 

 Often the motives of the choice may be unknown to the 

 chooser, yet it is none the less certain that a respect for shrewd- 

 ness and a liking for vivacity must count for a good deal. But, 

 even if we grant that there is a general demand for a fair amount 

 of brain power, this is no evidence that a more intellectual race 

 is being evolved. Evolution of higher powers takes place only 

 when through a change of environment the survival standard is 

 raised, otherwise elimination produces only fixity of type. Is 

 there any reason to believe that cleverness is more wanted in the 

 mass of men than two hundred years ago ? 



Com- It is very easy to overestimate the amount of selection ot 

 ! intellectual ability that goes on in the present day. Men's 

 tions perception of the facts is often overclouded by the large space 

 which competitive examinations fill in their imaginations and by 

 a misunderstanding bf their operation. There is hardly need to 



