PROBLEM 3. Behavior in Complex Ani?nals 



89 



Fig. 271 WJ:)at reflexes are 

 used as the basis for training 

 anifiials such as these to per- 

 joriii? (acme) 



food Stimulus and the dogs secreted sa- 

 liva. Pavlov called it a conditioned re- 

 flex; we prefer to call it a conditioned 

 response. A conditioned response is un- 

 learned as readily as it is learned. Thus 

 it is clearly different from a reflex in two 

 ways: it is learned, while a reflex is in- 

 born; and it may be unlearned or lost, 

 while a reflex is rarely lost unless cells 

 are injured. 



Conditioned responses are common. 

 The conditioned response is one of the 

 simplest of the learned acts. It often ac- 

 counts for the training of an animal. To 

 teach your dog to respond to your call, 

 you hold out some desired food and 

 whistle or call at the same time. The 

 smell of the food is the stimulus and he 

 comes. But as he smells the food he hears 

 your call; two stimuli attach themselves 

 to the response. Soon you can drop the 

 food stimulus and the call alone will 

 serve to make the dog come to you. As 

 a rule conditioning such as this does not 

 wear off, probably, because the dog 



finds a reward in coming to you even if 

 he gets no food. Some animals make the 

 substitution quickly; they learn easily. 

 Others need more frequent repetition. If 

 possible do Exercise i. 



A baby, too, acquires conditioned re- 

 sponses. At a very early age the baby's 

 mouth goes through sucking movements 

 at the sight of the bottle or the sound 

 of the mother's footsteps or any other 

 sounds associated with the usual feeding. 

 Can you think of other conditioned re- 

 sponses in the child? Conditioning in the 

 child is easy up to about the age of four. 

 But there are situations in which even an 

 adult may be conditioned. 



Other kinds of learned responses. 

 There are many learned responses which 

 are not conditioned responses. As a child 

 you learned to do many things which 

 now seem so natural to you that you 

 may not realize that they are learned re- 

 sponses; you have forgotten how diffi- 

 cult it was to learn them. Learning to 

 hold a spoon and feed yourself is one of 



