PROBLEM 



Behavior in Complex Animals 



duce striking physical changes in your 

 heartbeat, breathing, secretion of diges- 

 tive juices, peristaltic contractions, and 

 contractions of skeletal muscles. You 

 read earlier that anger causes the adrenal 

 glands to secrete more actively, bringing 

 about changes in many parts of the body. 

 This is also true of some other emotions. 



Other vertebrates, evidently, have 

 emotions too. In apes and in men the 

 feelings or emotions are shown in the 

 facial expression, but dogs and cats also 

 make clear to us how they feel. If you 

 have ever watched goats or lambs you 

 know how they kick up their heels in 

 play. Even fish can show anger, as dis- 

 played by the behavior of the Siamese 

 fighting fish. But to what extent, if any, 

 invertebrates have emotions is difficult 

 for us to determine. Perhaps a true brain 

 is needed for emotional behavior. The 

 less developed the brain, the less emo- 

 tional behavior is sho^vn. Experiments 

 with animals indicate that the emotions 

 are controlled by the lower centers of 

 the brain and by the autonomic nervous 

 system. 



Emotions and growing up. A very 

 young baby seems to have only three 

 emotions: fear, anger, and pleasure, and 

 they are called forth by a very limited 

 number of stimuli. Patting or rocking 

 calls forth pleasure; restraining its mus- 

 cular movements arouses anger; and a 

 loud noise or being dropped causes fear. 

 As the baby develops, the variety of 

 emotions increases and the number of 

 stimuli which may arouse these emotions 

 is increased enormously and with great 

 rapidity. In someone of vour age the 

 stimuli could not be listed, for they are 

 countless and they are somewhat differ- 



297 



Fig. 278 What emotiofi is this little girl express- 

 ing in her face and her whole body? (eva 

 luoma) 



ent in each person and different in any 

 one person at different times. And the 

 variety of emotions you may experience 

 M^ould take a long time to list. Try it by 

 doing Exercise 7. 



Our emotions may play us all kinds of 

 tricks; we often come to associate them 

 with quite unrelated objects or circum- 

 stances. For example, a young child 

 given its first taste of carrots may feel 

 "pleasure." But as he eats, an unexpected 

 noise may frighten him. Fear may thus 

 become associated with the food and 

 thereafter carrots will be unwelcome. 

 Can you give other examples of an emo- 

 tion \\ hich attaches itself to the wrong 

 stimulus? 



As you grow older and your experi- 

 ence with different situations and dif- 

 ferent people broadens, you will tend to 



