136 Animal Intelligence 



time than a dog with his whole life's business. In the asso- 

 ciations which are homologous with those of animals man 

 outdoes them and adds an infinity of associations of a 

 different sort. The primates would seem, by virtue of their 

 incessant curiosity and addition to experience not for any 

 practical purpose but merely for love of mental life, to 

 represent an advanced stage toward this tremendous 

 quantity of associations. In man not only this activity 

 and curiosity, but also education, increases the number of 

 associations. Associations are formed more quickly, and 

 the absence of need for self-support during a long infancy 

 gives time. Associations thus formed work back upon 

 practical life, and by showing better ways decrease the 

 need of work, and so again increase the chance to form 

 associations. The result in the case of a human mind to- 

 day is the possession of a thesaurus of valuable associations, 

 if the time has been wisely spent. The free life of ideas, 

 imitation, all the methods of communication, and the 

 original accomplishments which we may include under the 

 head of invention, make the process of acquisition in many 

 cases quite a different one from the trial and error method 

 of the animals, and in general much shorten it. 



Small as it is, however, the number of associations which 

 an animal may acquire is probably much larger than popu- 

 larly supposed. 



My cats and dogs did not mix up their acts with the 

 wrong sense-impressions. The chicks that learned the 

 series of twenty-three associations did not find it a task 

 beyond their powers to retain them. Several three-day-old 

 chicks, which I caused to learn ten simple associations in 

 the same day, kept the things apart and on the next morning 

 went through each act at the proper stimulus. In the hands 

 of animal trainers some animals get a large number of 



