BASIS OF PSYCHICAL-SOCIAL INDIVIDUALITY 613 



But in vertebrates distinctions between individuals may be recognized. It is 

 especially the development of conditioned reflexes which leads to the differen- 

 tiation between individuals of the same species, because individual distinctions 

 of a finer type depend upon individual experiences of a special kind, and 

 conditioned reflexes seem to play only a very small part in primitive organisms 

 under natural conditions, where we have essentially to deal with "forced 

 movements" based on non-conditioned reflexes. 



Even in the apparently most highly developed invertebrates, the social 

 insects, bees for example, rigid reflexes and complex reflex systems, instincts, 

 determine the very complex modes of their behavior. While environmental 

 changes may have a slightly modifying influence, in general these animals are 

 guided in a reflex manner by scents, colors, and certain spatial characteristics ; 

 also time factors, such as the position of the sun, may perhaps affect their 

 activities. While this interaction of some environmental factors with a com- 

 plex organization may lead to very complicated modes of behavior, still, the 

 latter remain essentially rigid and forced and are largely non-modifiable. 

 However, memories seem to play a certain part in the behavior of these 

 organisms, and further complications, in addition to those caused by condi- 

 tioned reflexes, are introduced by the changes taking place at some periods in 

 the life of the individuals, which may lead to changes in the reaction modes. 

 Although to a very limited extent the reactions of these animals have become 

 modifiable, in the main they are rigid and fixed. It is the complexity of these 

 reactions and their social nature, which are the distinctive features in the 

 behavior of the social insects and which raise their behavior co an apparently 

 very high level, making it comparable in certain respects to the social life 

 of higher vertebrates. 



While, as we have seen, there are no indications of marked individualiza- 

 tion in the strict meaning of this term, sharply defined group differences 

 exist in accordance with structural and functional differentiations within cer- 

 tain species of insects. The various species of ants differ and show grada- 

 tions in regard to their psychical-social behavior in a way analogous to the 

 differences and gradations in the structure and function of various organs, and 

 in the structure of the body as a whole. In general, the behavior patterns, 

 which are essentially based on inherited instincts, are similar in nearly related 

 insects and differ in further distant species ; but in some cases nearly related 

 species may present very different types of behavior, and relatively distant 

 species may show similar types of behavior; for example, certain bees are 

 non-social in their behavior pattern, while insects as distant as bees and ants 

 may have in common very complex social reaction systems. 



Fishes, representing the most primitive class of vertebrates, recognize to a 

 limited degree individuals and species. There are species differences in be- 

 havior ; on the whole, behavior patterns are similar in related, and quite different 

 in more distant species. Individuals belonging to the same species school to- 

 gether, joining their own species in preference to a strange one ; and conversely, 

 a certain school receives members of its own species and repels members of a 

 strange species. In the social dominance system, in which there are individuals 



