Making Mistakes Over and Over

I was always told to learn from my mistakes. Actually, I found it was more efficient (and less painful) to learn from the mistakes of others.

Anyway, learning from mistakes, your own or those of others, is called "adaptive learning" in which decisions are made in anticipation of expected consequences. Habitual responses don't satisfy this definition because they occur indepently of the consequences. In fact, repeating bad choices and behaviors is a common personal and social problem. Why do we do that?

A new research report shows that stress may be the culprit by causing a bias in decision-making strategies. Chronically stressed rats diminished their ability to make decisions based on expected consequences. After a standardized chronic stress procedure, rats were tested to see if there was any change in their ability to perform actions based on consequences of their behavior. In one experiment, control, non-stressed rats trained to press a lever for a particular reward drastically reduced their lever pressing when the basis for rewards was changed to eliminate a clear relation of lever pressing to delivery of reward. When the same contingency changes were made with the stressed group, the rats resorted to a habitual response pattern. A second test was given to a second group of rats in which one action (pressing the left lever) would yield a reward (food pellet) and another action (pressing the right lever) would lead to a different kind of reward (sucrose solution). Responses in both normal and stressed rats showed progressive learning gains with repeated training. Then on the last day of training one of the lever press action conditions was changed so that the lever did not have to be pressed to get a reward. Rats in control group quickly reduced their press rate on the lever that did not have to be pressed to get reward. But stressed rats pressed both levers the same, showing they were making choices out of habit rather adapting to the changed situation.

Stressed rats showed structural changes in the cerebral cortex, which would predict that dysfunctional decision capability may be impaired for a long time.

Thus, it appears that chronic stress created dysfunctional decision making in rats. Is chronic stress the reason that some people continue to make one bad choice after another? If so, their bad choices often have their own bad consequences that add to the stress. It sounds like a vicious circle to me. Maybe there is also a role for stress in "learned helplessness," which I have written about in my book. That is, when you fail at something, the failure itself is stressful. Too frequent failure leads to chronic stress, which in turn impairs your ability to learn from your mistakes and continue to make bad choices.

Source: Dias-Ferreira, E. et al. 2009. Chronic stress cause frontostriatal reorganiztion and affects decision-making. Science 325: 621-625.