HEALTH AND DISEASE 325 



To those who have studied the phenomenon of physical degeneration it 

 will be no surprise that tooth defects head the list of causes of rejection. 

 Dental caries, together with degeneration of the jaw bone and disease of 

 the periodontal tissues, combine to form the most universal scourge of 

 modern civilization. Examination made in public schools throughout the 

 country reveal that from 85 to 100 per cent, of the children are afflicted 

 with dental decay. 



From the evolutionary point of view, dental caries is a comparatively 

 modern disease with an affinity for civiHzed peoples. Dr. Weston A. Price, 

 whose extensive researches into the causes of this and related diseases have 

 attracted widespread attention, finds it to be practically nonexistent among 

 primitive peoples isolated from civilization. Price reports, further, that 

 even in the first generation after primitive races adopt the foods of white 

 civilization tooth decay appears, together with such evidences of evolu- 

 tionary degeneration as the narrowing of the face and the dental arches.^ 



Physical anthropologists, and particularly Dr. Earnest Albert Hooton, 

 of Harvard University, regard the condition of the teeth and dental arches 

 as of great evolutionary significance. Diseases of these structures may be 

 used as a measure of the physical degeneration of any race, for they are al- 

 most invariably accompanied by deterioration of other tissues. The nar- 

 rowing of the dental arch, depriving the teeth of normal room, causes 

 malocclusions which may result in gastric disorders. The narrowing of 

 the face may alter the shape and affect the capacity of the brain cavity. 

 These malformations usually are accompanied by a general diminution 

 and deterioration of bony tissues, notably the narrowing of the pelvis 

 which, in women, affects the reproductive function. 



But how, the reader may protest, is this talk of evolutionary degenera- 

 tion to be reconciled with studies which show that Americans are growing 

 taller and heavier each generation? There is impressive evidence on both 

 sides of this case, and much of it cannot be reconciled. It is more a matter 

 of weighing the evidence in order to see on which side the preponderance 

 lies. 



Several studies have shown Americans to be taller and heavier than Euro- 

 peans descended from the same stock. Other studies have shown second- 

 generation Japanese in California and off-spring of Europeans in Ameri- 

 can cities to be larger and better built than their parents. The most recent 

 study of this sort is that of the Metropolitan Life Insurance Company, 

 which shows that the average height of men beru'een the ages of 20 to 29 

 inclusive, examined at military induction centers in May, 1943, was 68.15 

 inches, or two-thirds of an inch greater than that of the same age group 

 among the first million men mobilized for war in 1917; that the proportion 

 of six-footers among men in their twenties is about one-third greater than 

 it was 25 years ago; and that the native women of the United States, in the 



'^ Nutrition and Physical Degeneration, p. 18. 



