THE IMPORTANCE OF SOCIAL LIFE 7I 



"widespread, fundamental automatic cooperation which has 

 survival value." He found a "substratum of social tendencies 

 that extends throughout the entire animal kingdom. From 

 this substratum social life rises by the operation of different 

 mechanisms and with various forms of expression until it 

 reaches its present climax in vertebrates and insects."* 

 While still a graduate student in zoology, Allee was directed 

 toward his Hfe's work when he found unmistakable evi- 

 dence of group attraction in lowly isopods, relatives of the 

 crayfish; and during a long life in which he has studied the 

 social attributes of many kinds of animals he writes that he 

 has never encountered a single asocial organism. Nor has 

 anyone else. The social tendencies extend from the lowest to 

 the highest. 



A distortion of Darwinism has led many writers in vari- 

 ous fields to underestimate his emphasis on the "mutual aid" 

 factor in evolution. They are too impressed with the sur- 

 vival value of rugged individualism; they tend to interpret 

 fitness in terms of physical aggressiveness only. Darwin was 

 fully aware of the survival value of social instincts, senti- 

 ments, and emotions. He pointed out that social instincts 

 lead an animal to take pleasure in the society of its fellows, 

 to exhibit a degree of sympathy, and to perform various 

 services. Among gregarious animals, he thought, those indi- 

 viduals which took the greatest pleasure in close association 

 would best escape danger, while those which cared the least 

 for their fellows, and tried to live alone, would perish in 

 greater numbers. Even among worms this Darwinian con- 

 tention is borne out. Allee found that worms injured by 

 X-rays lived longer when grouped after irradiation than 

 when left alone. Somehow the presence of their fellows 

 lent strength to the individuals. He was unable to identify 

 the factor, but his research, and that of many others, shows 

 that it is there. Darwin was greatly interested in the extent to 



* W. C. Allee, The Social Life of Animals (New York: W. W. Nor- 

 ton & Co., Inc., 1938), pp. 133, 274. 



