190 Animal Intelligence 
sions and impulses. But our interpretation of these results 
should not be too hasty. We must first consider several 
other possible explanations of the rapidity of learning 
by the monkeys before jumping to the conclusion that the 
forces which bring about the sudden formation of associa- 
tions in human beings are present.. 
L First of all it might be that the difference was due to the 
superiority of the monkeys in clear detailed vision. | It 
might be that in given situations where associations were 
to be formed on the basis of smells, the cats and dogs 
would show similar rapid learning. There might be, that is, 
no general difference in type of mental functioning, but 
only a special difference in the field in which the function 
worked. This question can be answered by an investigation 
of the process of forming associations in connection with 
smells by dogs and cats. Such an investigation will, I 
hope, soon be carried on in the Columbia Laboratory by 
Mr. Davis.' 
| Secondly, it might be that the superior mobility and more 
detailed and definite movements of the monkeys’ hands 
might have caused the difference.) The slowness in the 
case of the dogs and cats might be at least in part the result 
of difficulty in executing movements, not in intending them. 
This difficulty in execution is a matter that cannot be readily 
estimated, but the movements made by the cats and dogs 
would not on their face value seem to be hard. They were 
mostly common to the animals’ ordinary life. At the same 
time there were certain movements (e.g. depressing the 
lever) which were much more quickly associated with their 
respective situations by the cats than others were, and if 
we could suppose that all the movements learned by the 
monkeys were comparable to these few, it would detract 
1This, I regret, was not done [E. L. T., 19r1]. 
