The Mental Life of the Monkeys 191 



from the necessity of seeking some general mental differ- 

 ence as the explanation of the difference in the results. 



In the third place it may be said by some that no com- 

 parison of the monkeys with dogs and cats is valid, since 

 the former animals got out of boxes while the latter got in. 

 It may be supposed that the instinctive response to confine- 

 ment includes an agitation which precludes anything save 

 vague unregulated behavior. Professor Wesley Mills has 

 made such a suggestion in referring to the 'Animal Intelli- 

 gence' in the Psychological Review, May, 1899. In the 

 July number of the same journal I tried to show that 

 there was no solid evidence of such a harmful agitation. 

 Nor can we be at all sure that agitation when present does 

 not rather quicken the wits of animals. It often seems to. 

 However I should, of course, allow that for purposes of 

 comparison it would be better to have the circumstances 

 identical. And I should welcome any antagonist who should, 

 by making experiments with kittens after the fashion of 

 these with the monkeys, show that they did learn as sud- 

 denly as the latter. 



Again we know that, whereas the times taken by a cat 

 in a box to get out are inversely proportional to the strength 

 of the association, inasmuch as they represent fairly the 

 amount of its efforts, on the other hand, the times taken by a 

 monkey to get in represent the amounts of his efforts plus 

 the amount of time in which he is not trying to get in. It may 

 be said therefore that the time records of the monkeys prove 

 nothing, that a record of four minutes may mean thirty 

 seconds of effort and three minutes thirty seconds of sleep, 

 that one minute may really represent twice as much effort. 

 As a matter of fact this objection would occasionally hold 

 against some single record. The earliest times and the 

 occasional long times amongst very short ones are likely 



