132 Animal Intelligence 



COMPLEXITY OF ASSOCIATIONS 



An important question, especially if one wishes to rate an 

 animal on a scale of intelligence, is the question of how com- 

 plex 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, con- 

 versely, 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 happens 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 formation of such series animals are capable to a 

 very high degree. Chicks from 10 to 25 days old learned to 

 go directly through a sort of big labyrinth requiring a series 

 of 23 distinct and in some cases fairly difficult associations, 

 of which ii 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 

 complex association to be formed. Such were G (thumb 

 latch), J (double), K andL (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 position, and so feel then a different sense-impres- 

 sion from before, and thus turn the thing into a serial asso- 



