ANIMAL INTELLIGENCE. 9 1 



Complexity ok Associations. 



An important question, especially if one wishes to rale an 

 animal in a scale of intelligence, is the question of how complex 

 an association it can form. A man can learn that to open a 

 door he has to put the key in its hole, turn it, turn the knob, 

 and pull the door. Here, then, is a complex act connected with 

 the simple sense-impression. Or, conversely, a man knows that 

 when the ringing of a bell is followed by a whistle and that by 

 a red light he is to do a certain thing, while if any of the three 

 happen alone he is not to. How far, then, we ask, can animals 

 go along the line of increased complexity in the associations? 



We must not mistake for a complex association a series of 

 associations, where one sense-impression leads to an act such as 

 to present a new sense-impression which leads to another act 

 which in its turn leads to a new sense-impression. Of the for- 

 mation of such series animals are capable to a very high degree. 

 Chicks from lO to 25 days old learned to go direcUy through 

 a sort of big labyrinth requiring a series of 23 distinct and in 

 some cases fairly difficult associations, of which 1 1 involved 

 choices between two paths. By this power of acquiring a long 

 series animals find their way to distant feeding grounds and 

 back again. But all such cases are examples of the number, 

 not of the complexity, of animal associations. 



Some of my boxes were such as did give a chance for a com- 

 plex association to be formed. Such were G {thumb-latch), J 

 {double), K and L (triples) for the cats, and O (triple) for the 

 dogs. It would be possible for a cat, after stepping on the 

 platform in K, to notice that the platform was in a different po- 

 sition, and so feel then a different sense-impression from before, 

 and thus turn the thing into a serial association. The cat would 

 then be like a man who on seeing a door should feel only the 

 impulse to stick the key in the hole, but then, seeing the door 

 plus a key in the hole, should feel the impulse to turn the key 

 and so on through. My cats did not give any signs of this, 

 so that with them it was either a complex association or an ir- 

 regular happening of the proper impulses. Probably the same 

 was the case with dog i. Cats 10, u, 12 in L knew all the 

 movements separately before being experimented on with the 



