Berry, Imitation in White Rats. 359 



untrained rat observed that the other one was able to get out while 

 he was not, a gradual change took place. The untrained rat 

 began to watch the other's movements closely; he followed him all 

 about the cage, standing up on his hind legs beside him at the 

 string, and pulling it after he had pulled it, etc. We also saw 

 that when he was put back the immediate vicinity of the loop was 

 the point of greatest interest for him, and that he tried to get out 

 by working at the spot where he had seen the trained rat try. 



In the light of these facts it seems to me that imitation in white 

 rats has been conclusively established. The question now is as 

 to the nature of this imitation. Is it voluntary, instinctive or 

 automatic imitation ^ 



We have already seen that Small claims that there is no such 

 thing as voluntary, or inferential imitation, as he calls it, among 

 white rats. I readily admit that many of the instances of apparent 

 imitation may be satisfactorily explained as instinctive or automa- 

 tic imitation, but I wish to maintain that there are cases that can- 

 not be explained in this way. Small' in connection with his maze 

 experiment states that when two rats met in the maze one seldom 

 followed the other. This is entirely in keeping with the results of 

 my experiments, for I found that when two rats were put in the 

 same box together, one seldom followed the other. It was not 

 until the trained rat had got out a few times that the untrained rat 

 began to follow him. These facts cannot be explained on the 

 basis of instinctive following, as where the young follows the 

 mother, for in these experiments when one rat followed another 

 it was with a knowledge of the end to be attained by that following. 

 When experience of the end was lacking the following seldom took 

 place. For as a rule when two rats were put in the box together 

 they showed no particular tendency to take note of each other's 

 movements until one got out a few times; then the other would 

 follow him all about the cage. If a new rat was now put in with 

 the untrained one, the latter would followthe former just as readily 

 as he had followed the trained rat. Yet, if after a few minutes 

 the new rat did not succeed m getting out, the other would cease 

 imitating his movements. Watson states that young rats do 

 not track one another by the sense of smell, whereas after sexual 

 maturity is reached, the tracking may occur. = 



'Small. Mental Processes of the Rat. American Journal of Psychology, Vol. 12, p. n't,. 1901. 

 'Watson. Animal Education, p. 85. Chicago. 1903. 



