PROBLEM 3. Behavior m Complex 



performed with a large variety of ani- 

 mals. Chickens have been frequently 

 used and rats perhaps most often. Even 

 earthworms have been experimented 

 with. Boxes have been constructed with 

 a maze, a confusing network of paths, 

 only one of which leads to food at the 

 end. Animals have been put into such a 

 maze and observations made of their 

 attempts to reach food. The first success 

 was accidental. With repetition an ani- 

 mal will learn to find its way in a shorter 

 and shorter time. In one experiment the 

 following figures were obtained. On the 

 first attempt it took a rat 28 minutes, the 

 next time 11, then 12, 4, 4^, 5, 5, 2^, 2i, 

 2, and so on until after about the thir- 

 tieth time it ran through its maze to the 

 exit in less than half a minute. Between 

 the tenth and thirtieth performances 

 there were again several slight ups and 

 downs; on the seventeenth try, for in- 

 stance, it took the rat 3 minutes, but on 

 the whole the rat made better and bet- 

 ter scores. The rat was learning. Experi- 

 menting with rats in a simple maze is not 

 difficult. 



Professor Thorndike observed the be- 

 havior of cats, not in a maze, but in a 

 "puzzle box." This is a box made of slats 

 too close together for the cat to squeeze 

 through and closed with a door which 

 can be opened from the inside by means 

 of a lever. A hungry cat was placed in- 

 side. Food was placed outside the door. 

 After trying to get through the bars the 

 cat moved about and clawed the sides 

 until by accident it pressed on the lever 

 (trial and error). The first time it took 

 160 seconds. On successive trials these 

 scores in seconds were made: 40, 85, 22, 

 32, 10, 21, 12, 12, 18, 12, 10, 8, II, 8, and 8. 



Animals 



291 



Fig. 273 Professor E. L. Thorndike tested 

 chicks in this maze. At first the chicks fluttered 

 about wildly and ran back and forth until they 

 got out. After many trials the chicks learned to 

 find the correct exit with ahnost no errors. 

 (thorndike) 



The cat was learning to do what at first 

 it accomplished by accident. You could 

 arrange these figures in such a way that 

 they would mean more at a glance. See 

 Exercise 2. 



You, too, have learned by trial and 

 error and after many repetitions; you did 

 so in learning to feed yourself, to dress 

 yourself, and in the many other activities 

 you learned as a child. You can observe 

 yourself while solving a problem bv trial 

 and error if you do the Chinese ring 

 puzzle. See Exercise 3. Or try your suc- 

 cess in tracing your way through a maze 

 with a pencil point. See Exercise 4. 



