Studies of abnormal behavior in the rat. III. The development of behavior fixations through frustration.

Abstract

Using the Lashley Jumping Apparatus position habits were developed in 3 groups of rats under 3 exptl. conditions. In 1 group, the habits were developed by the presentation of an insoluble problem and in the other 2 by the rewarding of either the preferred or the non-preferred positional reaction. The strengths of the position habits were then measured. This was done by presenting the 3 groups with a discrimination problem which resulted in the punishment of 50% of the positional reactions. Animals failing to abandon their position habits after 200 trials were then punished for 100 trials whenever a response to position was made. Of the animals developing position habits through frustration in the insoluable problem 64% failed to abandon the position habit, and of the 2 groups developing position habits by reward, only 30% failed to abandon the habit. A discrimi- nation habit had actually been formed in all animals and merely failed to come to full expression in some of the animals because of the dominance of the position habits. This demonstrated that the persistence of the position habit was not due to inability to learn the discrimination problem, but rather to inability to replace the position habit. Because of the unusual strength of the position habits formed under conditions of frustration they were designated "abnormal fixations" to differentiate them from habit fixations occurring under the usual conditions of learning. Additional evidence for their abnormal character is also presented.