Animal Psychology 181 



In this connection one is also confronted with difficulties as in 

 other fields. Suppose one is attempting to see whether an animal can 

 distinguish between colors and then learn to go toward one hue rather 

 than another. Suppose now, that the ainmal does not show any more 

 inclination of going toward one color than toward another. This by no 

 means proves that the animal cannot distinguish, or is unable to learn, 

 that there are two colors. It may mean nothing more than that colors 

 make so little difference to the animal that there is no reason (motive) 

 for his choosing one rather than the other. In such an instance the 

 animal's reaction to both colors would be identical, and one could prove 

 little or nothing from its behavior. 



Another animal may be thought unable to learn because it tries a 

 problem a few times and then ceases to react at all to the stimulus. This 

 may be due entirely to fatigue on the part of the organs used, and not 

 to inability to learn. That is, the nerve receptors may become dulled 

 or tired by new stimuli which are foreign to the animal in its native 

 career. 



Or again, some sensation may be pleasant to an animal only if 

 secondary factors are present, such as the taking of food only when it 

 is hungry or when the body is in good health. But surely the rejection 

 of food does not mean that the animal either can or cannot discriminate 

 between foods. We often will not eat one kind of food, while another 

 is relished, or we often will just as readily eat ice cream, candy, or fruit, 

 and show just as much desire for the one as for the other; but this 

 certainly does not mean that we do not know the difference between 

 these three types of edibles. 



Then, too, the state of health makes a tremendous difference in 

 what an animal will choose. Dogs and cats eat certain plants at certain 

 times, but at other times they will not touch these foods. But do they 

 not know the difference between these plants and other food? 



Then, too, an animal may be trained to do certain things, but suppose 

 it does these things without having been trained. Can one not argue 

 as well that the animal merely stumbled upon doing the act, and then 

 doing it often, the nerve-arcs became fixed and the animal can no longer 

 help itself? It is now a habit. 



Habits are but acts performed by fixed nerve-arcs. 



The question may arise as to what difference there would be between 

 psychology and physiology if all we are to study consists of nerves and 

 reactions. Really, there would be no difference in content of the two 

 sciences, the difference would consist in emphasis. The psychologist 

 lays stress on emotions, feelings, etc., and the physiologist on the simple 

 observable reaction which follow a given stimulus. The psychologist, 

 in other words, wants to know how the animal feels and what it has 

 in its consciousness when a stimulus is applied and its actions are 

 changed. 



