Table 2
| Cat 1 | A B C D₁ D Z I |
| Cat 2 | C D₁ D E Z H J I K |
| Cat 3 | A C E G H J Z I K |
| Cat 4 | C F G D Z H J I K |
| Cat 5 | C E Z H I |
| Cat 6 | A C E Z |
| Cat 7 | A C |
| Cat 10 | C I A H D L |
| Cat 11 | C I A H D L |
| Cat 12 | C I A H D L |
| Cat 13 | A C D G Z |
Fig. 9.
The advantage due to experience in our experiments is not, however, the same as ordinarily in the case of trained animals. With them the associations are with the acts or voice of man or with sense-impressions to which they naturally do not attend (e.g. figures on a blackboard, ringing of a bell, some act of another animal). Here the advantage of experience is mainly due to the fact that by such experience the animals gain the habit of attending to the master’s face and voice and acts and to sense-impressions in general.
I made no attempt to find the differences in ability to acquire associations due to age or sex or fatigue or circumstances of any sort. By simply finding the average slope in the different cases to be compared, one can easily demonstrate any such differences that exist. So far as this discovery is profitable, investigation along this line ought now to go on without delay, the method being made clear. Of differences due to differences in the species, genus, etc., of the animals I will speak after reviewing the time-curves of dogs and chicks.
In the present state of animal psychology there is another value to these results which was especially aimed at by the investigator from the start. They furnish a quantitative estimate of what the average cat can do, so that if any one has an animal which he thinks has shown superior intelligence or perhaps reasoning power, he may test his observations and opinion by taking the time-curves of the animal in such boxes as I have described.