STUDIES ON THP: MENTAL LIFE OF ANIMALS. 



555 



Another sort of imitation ought also to be eliminated — that shown, 

 for example, in a flock of sheep. The hrst ones leap over a barrier 

 which is taken away before all the flock have passed: the next sheep 

 jumps as if to get over a barrier, although it is not there, and five or 

 six others do the same. In appearance — but only in appearance — this 

 is a phenomenon of imitation. In fact, the reproduction of the act 

 accomplished by the first animals may depend upon very special cir- 

 cumstances peculiar to animals that live in flocks. " It is possible that 

 among gregarious animals there may be elaborate connections in the 

 nervous system which allow the sight of certain peculiar acts in another 

 animal to arouse the innervation leading to those acts, but that these 

 connections are limited. The reactions, according to this view, are spe- 

 cific responses to definite signals, comparable to any other instinctive or 

 associational reaction. The sheep jumps when he sees the other sheep 

 jmnp, not because of a general ability to do what he sees done, but 

 because he is furnished with the instinct to jump at such a sight, 

 or because his experience of following the flock over bowlders and 

 brooks and walls has 



got him into the habit 

 of jumping at the spot 

 where he sees one 

 ahead of him jump; 

 and so he jumps even 

 though no obstacle be 

 in his wav." There is 



(^ 



nra/ 



present at tne same Fig. lO. — Labyrinths used in experiments with ohipkcns. (Thorn- 

 time a phenomenon of <iii^e, p. 35.) 

 hereditary instinct and of personal experience. Primitively, the sheep 

 who now imitates did not jump unless the external elements calling 

 for that act were present and especiall}" unless the obstacle was present; 

 now he jumps '"when only the nonessentials are present."" Besides, 

 "these limited acts may be the i)rimitive, sporadic beginnings of the 

 general imitative faculty we find in man.'' In an}" case, the very fact 

 that diverse interpretations arc possible obliges us to leave out of 

 consideration this kind of imitation in the present investigsition. 



The imitation which we are to study here must be imitation in the 

 precise and strict sense of the word, understood as the transfer to 

 one's own personality of an association formed by another. 



V. 



1. Experiments with chickens. — Two chickens, Nos. 64 and <)B. were 

 shut in a cage from which one could get out only by crawling under 

 the wire screening at a certain spot or by walking up an inclined pU 



aThorndike, loc. cit., p. 49. 



me 



