THE DISPLAY OF ENERCIY 



379 



is fitted to perform a very limited number of unchangeable acts, are 

 rigid. The latter, on the other hand, are plastic, extremely flexible 

 and adaptable, capable in some instances of playing a Chopin noc- 

 turne, or in others of fashioning the cunning work of a Cellini. 



Habit Formation 



The patterns of behavior that we call habits are closely allied to 

 native behaviors. If animals can make associations, any act which 

 comes as a result of a contiguity of stimulation and useful associa- 

 tion tends to be repeated. If there are many repetitions the per- 

 formance of such an act becomes more and more certain. In other 

 words, it becomes a habit. It has been said that our lives are 

 bundles of habits. This is particularly true of man, since many of the 

 activities learned in early life, such as walking, learning to drive a car, 

 riding a bicycle, skating, swimming, writing, typewriting, and hun- 

 dreds of other activities common to this machine age, are habitual. 



One object of education is the training of different cerebral areas 

 so that they will do their work efficiently. In learning to write one 

 exerts a conscious effort in order to make the letters at first. Later, 

 the actual forming of letters is done without conscious effort, for by 

 training the act has become habitual. 



Conditioned Behaviors 



More than thirty years ago the famous Russian physiologist 

 Pavlov began a series of experiments that have changed much of 

 our thinking regarding the 

 fixity of animal behavior. His 

 best known work was done 

 with dogs. It is proven that 

 when food is offered to a 

 dog saliva is secreted. This 

 effect is partly psychic and 

 partly mechanical, as can be 

 seen when one thinks of a 

 particularly sour pickle or 

 lemon, or chews dry food. 

 Pavlov found that the dog's 

 saliva, which was normally 



f-^ -f^paroticC 

 inUmoa duct t^JJ 'dlcincC 



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external 

 t-ube 



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 gland- 



drop of.^alivtt^ 



Diagram to show Pavlov's experiment. 

 Under what conditions would saliva be 

 caught in the tube? Explain why he ob- 

 tained a conditioned reflex. 



secreted when the dog saw food, could be caused to flow by the 

 ringing of a bell, or by the presentation of a plate of a given color. 



