CHAPTER XXV 



INSTINCTS AND HABITS 



Questions. 1. Which is more rehable, our instincts or what we learn ? 

 2. Can people act against their instincts ? 3. Have all races the same in- 

 stincts ? 4. Can human nature be changed ? 5. Why do some people 

 learn more easily than others ? 6. Why do we learn more easily at some 

 times than at others ? 7. Why do we learn some things more easily than 

 others ? 8. Are there ways of making learning easier ? 9. Can old habits 

 be broken ? 



197. Instinctive acts. Among the most striking and interest- 

 ing facts to be observed in animals is the precise manner in 

 which they perform certain acts. Think of the bird making a 

 nest, the wasp paralyzing caterpillars, bees building wax cells, 

 a dog following a scent. In most cases the animals perform 

 these activities perfectly the first time they try. Indeed, in 

 the case of insects and many other animals, there is only one 

 try ! The wasp, for example, builds her nest, accumulates food 

 in it, lays her eggs, and then dies, never having a chance to see 

 her offspring, just as she never saw her parents: the animal 

 could never have learned to do what it does. Such unlearned 

 activities are called instinctive. They depend, like reflexes, 

 upon the animal's being born with a set of nerve connections 

 tying together receptors and effectors. In many cases we can 

 analyze an instinctive act into a series of reflexes. In many 

 cases the instinct shows itself when the animal is well along in 

 its development, but nevertheless it rests upon structures that 

 are inborn. 



198. Instincts not perfect. To many people the word instinct 

 suggests an act or a mode of behavior that is perfectly adapted 

 to the needs of the animal in its environment. It is also some- 

 times supposed to stand for a very shrewd kind of unconscious 



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