AND PERSONALITY 



Is the Eskimo, therefore, the most intelligent of human 

 beings ? A large brain is required in man in the arctic for 

 the same reason that a large brain is required in the warm- 

 blooded whale in the arctic, in the warm-blooded walrus, 

 the warm-blooded seal, the warm-blooded caribou, and the 

 Shetland pony as a defense, through high oxidation, to 

 maintain the warm-blooded state. On the biological princi- 

 ple that Dr. Quiring and I established, that I gram of brain 

 is required to execute 12,115 small calories in 24 hours, the 

 Eskimo, despite his igloo, despite the furs he wears, is in 

 need of an intense fire, that is, a high metabolism burning 

 within his own protoplasm to maintain his body tempera- 

 ture at 98.6?. 



The large brain of the Eskimo can be accounted for on 

 the basis of the higher requirement for the maintenance of 

 the warm-blooded state in the cold arctic. What of the 

 thinking part of the brain of the Eskimo ? The size of the 

 thinking part of the brain is in ratio to its survival value. 

 In the Eskimo the survival value of the thinking brain 

 is higher than in the Negro of the tropics because the 

 Eskimo must control fire, clothe himself, build igloos, 

 construct kayaks, and fashion tools by which to hunt and 

 fish under more difficult conditions than the Negro in 

 the tropics. The thinking brain of the Eskimo, therefore, 

 would have greater survival value than that of the Negro 

 in the tropics. But the survival value of the thinking brain 

 of the Eskimo is not so high as the survival value of the 

 thinking brain of civilized man in the temperate zones, 

 where food, clothing, and shelter must be man-made in 

 contrast to the natural food in the flesh of the arctic and 

 the fruit of the tropics. 



Thus it may be seen that the extremes of cold in the 

 arctic and of heat in the tropics have profoundly influenced 

 the evolution of the brain, the thyroid gland, and the blood 

 volume of man. The gift of a large brain and a large thyroid 

 gland to man of the temperate zones provided the back- 



235 



