360 'Journal of Comparative Neurology and Psychology. 



While maintaining that these are instances of voluntary imita- 

 tion, I do not maintain that the rats display a grade of intelligence 

 equal to that displayed by the monkey who pulled the plug after 

 seeing the other monkey pull it. The nature of this voluntary 

 imitation is determined by the intelligence of the animal imitating. 

 This means that many of the wonderful stories of the remarkable 

 feats of imitation will have to be taken with the proverbial grain 

 of salt. That this is true is at once evident, when we consider 

 how a rat learns to get otit of a box. When put in the box he 

 first tries to get out at the place nearest to the food, but not suc- 

 ceeding there he gradually works away from that spot until he has 

 tried almost every spot in the box, or until he pulls the string that 

 opens the door. Then his attention being attracted to the door 

 by the sound it makes in opening, he runs to it and passes out to 

 the food. When he is put back, take note of w^hat happens. 

 Does he run at once to the string, pull it and open the door .^ By 

 no means. He first tries the door and finding it closed he makes 

 many random movements before starting in the general direction 

 of the string. After nosing about in its vicinity for a time he finally 

 succeeds in finding it and pulling it, and thus escapes. It is not 

 until he has got out many times that he goes at once to the string, 

 pulls it and passes out, without first making a number of useless 

 random movements. 



These facts in regard to the way the rat learns to get out of a 

 box are of vital importance in helping us to decide what we may 

 reasonably expect from the rat in regard to imitation. If, when a 

 rat by chance pulls the string and hears the door open, passes out 

 and is fed, it cannot go directly to that string when put back, why 

 should we expect a rat that has merely witnessed the performance 

 to be able to do it ? The rat that opens the door not only sees the 

 string and sees his paw pull it, but he has in addition all the sensa- 

 tions that are connected with the movement of pulling the string, 

 while the rat that looks on has only the visual sensation, no kinaes- 

 thetic sensations. It seems to me that in the light of these facts 

 we ought to be able to say a priori that no ordinary rat (unless by 

 chance) would be able to open a door by pulling a string, simply 

 from having seen another rat do it, without first making a number 

 of random movements. 



All that we can expect one rat to learn from watching another 

 rat get out is, that if he tries the same part of the cage tried by the 



