COORDINATION AND BEHAVIOR 



557 



inheriting its own particular types of in- 

 stincts. Where simple reflexes end and in- 

 stincts begin, it is difficult to state. 



Habit formation, learning, 

 and intelligence 



During the study of the behavior of lower 

 animals, experiments have been devised, as 

 in the crayfish, that seem to indicate the 

 formation of habits. Habit formation among 

 the vertebrates is quite common. It consists 

 of the development of a particular type of 

 behavior as a result of previous experience. 

 Driving an automobile, tying a shoe lace, 

 and winding a watch all become more or less 

 automatic as the result of a constant repeti- 

 tion of reflexes. Habits are of great value 

 since they enable us to perform acts without 

 conscious effort. 



Learning differs from habit formation 

 since it involves replacement of the normal 

 or usual stimulus by another as the result 

 of repeated association. Such a reaction de- 

 pends to a large extent on conditioned re- 

 flexes. A conditioned reflex may be illus- 

 trated by the famed physiologic studies on 

 the dog. The salivary glands of a newborn 

 dog are reflexly stimulated when it tastes 

 food, and they respond by pouring saliva 

 into the mouth. As the dog grows older, the 

 sight of food calls forth the outpouring of 

 saliva before the food has been tasted; thus 

 the taste of the food is replaced by the sight 

 of the food. The dog learns by experience 

 that when he sees food, he will soon taste it; 

 and nervous pathways are developed by the 



sight of food that bring about salivary 

 stimulation. The investigator rang a bell 

 each time food was presented and found 

 that after a few repetitions the dogs secreted 

 saliva when the bell was rung without the 

 presence of food. Thus one conditioned re- 

 flex became the basis for another. 



The ability of an animal to form con- 

 ditioned reflexes determines largely its ca- 

 pacity to learn by experience. Retention of 

 what has been learned by experience is 

 called memory. The intelligence of an ani- 

 mal depends on its ability to profit by ex- 

 perience. Intelligent behavior is manifested 

 to a high degree by man, to a lesser degree 

 by other mammals and birds, and almost 

 not at all by the rest of the animal kingdom. 

 Next to man, anthropoid apes and then the 

 monkeys exhibit the greatest development 

 of intelligence. 



SELECTED COLLATERAL 

 READINGS 



Best, C.H., and Taylor, N.B. The Living Body, 

 A Text in Human Physiology. Holt, New 

 York, 1952. 



Gardner, Ernest. Fundamentals of Neurology. 

 Saunders, Philadelphia, 1952. 



Hoskins, R.G. Endocrinology. Norton, New 

 York, 1950. 



Parker, G.H. Animal Colour Changes and 

 Their Neurohumours. Cambridge Univ. 

 Press, London, 1948. 



Scott, J. P. Animal Behavior. Univ. Chicago 

 Press, Chicago, 1958. 



Turner, CD. General Endocrinology. Saun- 

 ders, Philadelphia, 1948. 



