292 THE PRINCIPLES OF HEREDITY 



deduction, reaching reasoned conclusions. In vain have I 

 laboured if I have failed to convince him that almost all 

 man's inborn impulses to action, his instincts, have under- 

 gone regression, or have become subservient to this one great 

 faculty. But if he is convinced, as I think he must be, for 

 the evidence is overwhelming, then he must believe also that 

 the different races of mankind cannot differ greatly as regards 

 their inborn impulses. They can differ greatly only as re- 

 gards their capacities for making and utilizing acquirements, 

 and more particularly as regards the acquirements they 

 actually do make. Possibly this or that instinct, for example, 

 the sexual or the parental, has undergone more regression in 

 one race than in another. Possibly this or that instinct, for 

 example the sportive or imitative, has reached a higher stage 

 of evolution in this race than in that. But so entirely de- 

 pendent for survival during untold centuries has man been 

 on his memory and its corollary, intelligence, that it is in- 

 credible that there can be surviving any great racial differences 

 in instincts. Whatever instincts any race possesses are use- 

 ful to every other race to a nearly equal degree. Whatever 

 instincts any race has lost must long have been useless to 

 every race, and therefore must have been almost, if not quite, 

 lost by all. As a matter of fact no inborn impulse to act, 

 nor inborn power of co-ordinating muscles for action, can be 

 named concerning which there is clear evidence that any 

 race surpasses any other. The infants of all races are born 

 equally helpless, and they all develop the same instincts, 

 apparently to the same extent. Everything, therefore, which 

 has been written, for instance, about the wonderful instincts 

 of the savage as compared to the civilized man has been 

 founded on a misuse of the term instinct, on a misunder- 

 standing of comparative psychology. 



466. The brains of some races are relatively long and 

 narrow ; those of the others are shorter and wider. We are 

 unable to say for certain what these inborn differences of 

 shape imply mentally. Probably they imply no more than 

 similar peculiarities of the hand imply as regards its function. 

 A man with a relatively short hand is able to use it to much 

 the same effect as a man with a long hand. There is no real 

 evidence proving that short-headed men have, on that account, 

 mental characters different from long-headed men. 1 As a 



1 A tribe of American Indians were accustomed to flatten the fore- 

 heads of their children by pressure. There is no evidence that any 

 mental alteration resulted. Probably the shape of the brain, a soft 

 organ, is determined by the shape of the skull, and not vice versa. In 



