Individuals had less physical stamina and impulse control and increased difficulty with problem-solving activities after completing a variety of tasks that required some measure of self-control, according to Roy F. Baumeister, Ph.D., of Florida State University.
The finding may be helpful in treating a number of behavioral health problems, from gambling disorders to alcoholism.
"Learning more about how to maintain, increase and replenish this resource may hold one promising key to helping people avoid addiction," says Baumeister.
The study appears in the February 2003 issue of Alcoholism: Clinical and Experimental Research.
There are three main theories about how self-control operates, according to Baumeister. One theory suggests that self-control depends on an energy or strength like "willpower," while a second theory considers self-control as a skill to be learned. Yet another theory views self-control as a thought process, where individuals process their different behavioral options and choose a course of action after analyzing their situation.
To test these theories, Baumeister and colleagues designed a series of studies to determine whether self-control could be depleted, which would indicate that it was more like willpower than a skill or thought process.
For one experiment, individuals were asked to stifle or exaggerate their emotions while watching a disturbing video. Afterward, their physical stamina was tested with a handgrip device. In another study, hungry participants were tempted with chocolate and freshly baked cookies before working on difficult geometric puzzles. In all cases, participants who exercised self-control were less able to complete the second task.
"Resisting temptation consumed an important resource, which was then less available to help the person persist in the face of failure," Baumeister explains.
He suggests that sleep may be one way that individuals can replenish self-control.
"Most forms of self-regulation failure escalate over the course of the day, becoming more likely and more frequent the longer the person has been deprived of sleep," according to Baumeister, who notes that positive emotional experience may also help replace expended self-control energy.
Self-control exercises, like food diaries or efforts to regulate emotions, may help build the "strength" of self-control over the long run, although these findings are still preliminary.
This study was supported by the National Institutes of Health.
FOR MORE INFORMATION
Health Behavior News Service: (202) 387-2829 or www.hbns.org.
Interviews: Contact Roy Baumeister, Ph.D., at (850) 644-4200 or baumeister@darwin.psy.fsu.edu.
Alcoholism: Clinical and Experimental Research: Contact Mary Newcomb at (317) 278-4765 or mnewcomb@iupui.edu, or visit www.alcoholism-cer.com.