MENTAL DEFECTIVENESS 89 



word-blind and figure-blind. He is cruel to the cat, appropriates to 

 his own use the property of others, and insists vehemently upon having 

 what he wants at whatever inconvenience to another. He is now a 

 low-grade imbecile without moral ideas. He will prove himself not to 

 be " feeble-minded " if, as he approaches puberty, all of these and the 

 other socially important undeveloped conditions prove, under fair 

 culture, capable of development up to the corresponding "normal" 

 conditions. Defectiveness is thus a persistent infantile condition of 

 one or more characteristics; a failure of certain socially important 

 traits to develop. 



Now there is a well-known biological principle that " ontogeny 

 recapitulates phylogeny " — that the child in his development passes 

 through the same series of physical and mental stages that the adults 

 did in the successive generations of the race's development. So we 

 may infer that man's remote ancestors did not go in their adult stage 

 beyond the point where this infant-man is now. Indeed, the adult 

 apes, nearest allies of our ancestors, show the same inability to talk, to 

 dress, to regard property rights and to be gentle and considerate toward 

 others that the infant shows. And we can not escape the conclusion 

 that the gradual acquisition of social traits by the normal child follows 

 much the same road as the evolution of social man from non-gregarious 

 apes. But, there are men who never develop these social traits. And 

 if we study the pedigrees of such men carefully (and many of them 

 have been studied for six or seven generations) we trace back a con- 

 tinuous trail of the defects until the conclusion is forced upon us that 

 the defects of this germ plasm have surely come all the way down from 

 man's ape-like ancestors, through 200 generations or more. This 

 germ plasm that we are tracing remains relatively simple ; it has never 

 gained (or only temporarily, at most) the one or the many character- 

 istics whose absence we call, quite inadequately, defects. Feeble-mind- 

 edness is, thus, an uninterrupted transmission from our animal an- 

 cestry. It is not reversion; it is direct inheritance. 



To summarize: Man is evolving and in that evolution he has lost 

 some physical traits and gained some mental ones. But neither in 

 their losses nor in their gains have all strains evolved to the same extent. 

 Some races have lost the skin pigment, but others have made little 

 progress in this direction. We are getting rid of our body coat of 

 hair, but the Akkas of the Upper Nile and special smaller strains have 

 a very hairy body, and so appendix and tail (coccyx) show variations 

 that run in families. Likewise in the acquisition of mental traits, 

 whole races differ in their ability to speak, to count, to foresee. The 

 Ethiopian has no more need for thrift than the tropical monkey and 

 has not acquired it. It is not surprising that there are strains, even 



