Experimental Study of Associative Processes 27 



cient number of trials, he failed to get out, the case was re- 

 corded as one of complete failure. Enough different sorts 

 of methods of escape were tried to make it fairly sure that 

 association in general, not association of a particular sort of 

 impulse, was being studied. Enough animals were taken 

 with each box or pen to make it sure that the results were 

 not due to individual peculiarities. None of the animals 

 used had any previous acquaintance with any of the 

 mechanical contrivances by which the doors were opened. 

 So far as possible the animals were kept in a uniform state 

 of hunger, which was practically utter hunger. 1 That is, 

 no cat or dog was experimented on, when the experi- 

 ment involved any important question of fact or theory, 



1 The phrase 'practically utter hunger' has given rise to misunderstand- 

 ings. I have been accused of experimenting with starving or half-starved 

 animals, with animals brought to a state of fear and panic by hunger, and 

 the like ! 



The desideratum is, of course, to have the motive as nearly as possible of 

 equal strength in each experiment with any one animal with any one act. 

 That is, the animal should be as hungry at the tenth or twentieth trial as at 

 the first. To attain this, the animal was given after each 'success' only 

 a very small bit of food as a reward (say, for a young cat, one quarter of a 

 cubic centimeter of fish or meat) and tested not too many times on any one 

 day. 'Utter hunger' means that no diminution in his appetite was noted 

 and that at the close of the experiment for the day he would still eat a hearty 

 meal. After the experiments for the day were done, the cats received 

 abundant food to maintain health, growth and spirits, but commonly some- 

 what less than they would of their own accord have taken. No one of the 

 many visitors to the room mentioned anything extraordinary or distressful 

 in the animals' condition. There were no signs of fear or panic. 



Possibly I was wrong in choosing the term ' utter hunger ' to denote the 

 hunger of an animal in good, but not pampered, condition and without food 

 for fourteen hours. It is not sure, however, that the term 'utter hunger' 

 is inappropriate. The few reports made of experiments in going without 

 food seem to show that, in health, the feeling of hunger reaches its maximum 

 intensity very early. It is of course not at all the same thing as the complex 

 of discomforts produced by long-continued insufficiency of food. Hunger 

 is not at all a synonym for starvation. 



