256 BODY CONTROL AND HABIT FORMATION 



ing for something it wanted. This would in a way be an instinc- 

 tive act. Can you explain how? 



When you first learned to write, did you think about making 

 the letters of the words you wrote? Do you now? How do you 

 account for the ease with which you now write ? 



What is the chief difference between the instinctive act of the 

 baby learning to walk and the act of writing? Do we think about 

 writing now ? Did we think about it when we began to learn ? 

 An act consciously repeated many times eventually becomes a 

 habit. Might a habit be formed through the unconscious repeti- 

 tion of an act? 



Conclusion. — 1. What is an instinct? 



2. What is a habit? How might it be formed? 



3. What is the difference between instinct and habit ? 



Problem 228 : To study the mechanism of habit formation. 



NOTE. — The formation of a habit involves the simplifying of a complicated 

 process. In an act of thought, e.g., picking up a toothbrush from the washstand (see 



diagram) the eye sees the brush and relays the 

 message through some sight cells to a nerve center 

 in the back of the brain (O.C.). From there the 

 message is again relayed to (M.C.), where the 

 impulse is originated to pick the brush up. This 

 results in a message being sent by another relay 

 of several sets of cells down the spinal cord to 

 the muscles of the arm where the fibers from this 

 neuron end in the muscles. 



Now if the act becomes habitual, as it does 

 when we brush our teeth each morning, the 

 stimulus caused by the sight of the brush causes 

 a short circuit of the impulse which goes to O.C. 

 and then directly down the spinal cord. 



The Course taken by the 

 Act of Thought. 



O.C. 



nerve center; M.C., 

 thought center. 



Conclusion. — 1. If M.C. is the 

 thought center, then what does habit 

 forming do? 



2. Would it be better to make a 

 problem of brushing your teeth each morning or to do it auto- 

 matically (by habit) ? 



3. Just how is a habit formed in the nervous center? 



4. Of what advantage are habits ? 



