The conventional wisdom is that people either have it or they don’t. If they have self-control, they can stick to a diet, stop smoking, study for an exam and just say no to the urge to goof off.
Apparently, that’s not entirely true. Researchers have found that we have limited resources to control our behavior. When we exhaust those resources, our ability for self-control is depleted. So, we quit smoking but can’t resist overeating.
Michael Inzlicht of the University of Toronto Scarborough, along with his colleague Jennifer Gutsell, had research subjects suppress their emotions while watching an upsetting movie. They had to exert self-control to do this. Then the subjects were asked to complete a task that required a lot of self-control: naming the color of printed words, saying “red,” the color of the printed word, when the printed word actually read “green.”
They found the people who held back their tears and scored great self-control watching the movie performed worse than others on the task. They had depleted their resources for self-control.
In an e-mail, Inzlicht explained that the anterior cingulate cortex in the brain, which acts like a watchtower telling us when our actions are out of line with our goals, is less efficient and fires sub-optimally after an initial act of self-control.
Inzlicht said limited resources of self-control could help explain impulsive criminal behavior. Some research has shown people react more aggressively after provocation when their self-control resources are depleted. He thinks his study has implications for future interventions designed to help people change their behavior.
The research article appears in the November issue of Psychological Science, a journal of the Association for Psychological Science.