206 



Changing Human Nature 



CONTRAST BETWEEN MAN'S FAMILY AND APE FAMILY 



(After Osborn) 



Pro-Human Characteristics 



1 Progressive intelligence; rapid 



development of forebrain 



2 Ground-living biped; habit 



adapted to rapid travel and 

 migration over open country 



3 Development of the walking 



and running type of foot and 

 great toe 



4 Shortening arms and lengthen- 



ing legs 



5 Walking and running power of 



the foot enhanced by enlarge- 

 ment of the great toe 



6 Development of the tool- 



making thumb 



7 Adaptation and design of im- 



plements of many kinds in 

 wood, bone and stone 



8 Design and invention directed 



by the intelligent forebrain 



9 Use of arms and tools in offense 



and defense, and in the arts 

 of Hfe 



10 Use of legs for walking, run- 



ning and travel to escape 

 from enemies 



1 1 Escape from enemies by vigi- 



lance, flight and concealment 



12 Tree-climbing by embracing 



main trunk with the arms 

 and limbs, after the manner 

 of the bear 



Pro-ape Characteristics 



Arrested development and brain- 

 size 



Arboreal to hyper-arboreal quadru- 

 manal; habit adapted to living 

 chiefly in trees 



Quadrupedal habit followed when 

 walking on the ground 



Lengthening arms and diminishing 

 legs 



Grasping power of the big toe for 

 climbing, modified when walking 



Loss of thumb and absence of tool- 

 making power 



Adaptation of the foot and hind 

 limbs to the art of tree climbing 



Design limited to the construction 

 of very primitive tree nests 



Use of the arms chiefly for tree- 

 climbing, and secondarily for the 

 prehension of food and grasping 

 of the foe 



Use of legs in tree climbing and 

 limb grasping 



Escape from enemies by retreat 

 through branches of trees 



Tree-climbing always along 



branches, never by embracing the 

 main limbs and trunk 



