THE COMPARATIVE PSYCHOLOGY OF MA^. 259 



greater quantity of energy in which this greater mental mass shows 

 itself. Hence a series of inquiries, of which these are some : (a.) 

 What is the relation between mental mass and bodily mass ? Mani- 

 festly, the small races are deficient in it. But it also appears that 

 races much upon a par in size as, for instance, an Englishman and a 

 Damara diti^er considerably in mental mass, {h.) What is its relation 

 to mass of brain? and, bearing in mind the general law that, in the 

 same species, size of brain increases with size of body (though not in 

 the same proportion), how far can we connect the extra mental mass 

 of the higher races with an extra mass of brain beyond that wliich 

 is proper to their greater bodily mass ? (e.) What relation, if any, is 

 there between mental mass and the physiological state expressed in 

 vigor of circulation and richness of blood, as severally determined by 

 mode of life and general nutrition? {d.) What are tlie relations of 

 this trait to the social state, as predatory or industrial, nomadic or 

 agricultural ? 



2. Mental Complexity. How races differ in respect of the more or 

 less involved structures of their minds will best be understood, on re- 

 calling that unlikeness between the juvenile mind and the adult mind 

 among ourselves which so well typifies the unlikeness between the 

 minds of savage and civilized. In the child we see absorption in sj^e- 

 cial facts. Generalities even of a low order are scarcely recognized ; 

 and there is no recognition of high generalities. We see interest in 

 individuals, in personal adventures, in domestic affairs; but no in- 

 terest in political or social matters. We see vanity about clothes and 

 small achievements ; but little sense of justice : witness the forcible 

 appropriation of one another's toys. While there have come into play 

 many of the simpler mental powers, there has not yet been reached 

 that complication of mind which results from the addition of powers 

 evolved out of these simpler ones. Kindred differences of complexity 

 exist between the minds of lower and higher races ; and comparisons 

 should be made to ascertain their kinds and amounts. Here, too, there 

 may be a subdivision of the inquiries : (.) What is the relation be- 

 tween mental complexity and mental mass ? Do not the two habitu- 

 ally vary together ? {h.) What is the relation to the social state, as 

 more or less complex ? that is to say. Do not mental complexity and 

 social complexity act and react on each other ? 



3. Rate of Mental Development. In conformity with the biologi- 

 cal law, that the higher the organisms the longer they take to evolve^ 

 members of the inferior human races may be expected to complete 

 their mental evolution sooner than members of the superior races ; 

 and we have evidence that they do this. Travelers from all regions 

 comment, now on the great precocity of children among savage and 

 semi-civilized peoples, and now on the early arrest of their mental 

 progress. Though we scarcely need more proofs that this general 

 contrast exists, there remains to be asked the question, whether it is 



