"Hey, You're Wearing Me Out!"

I used to jog a fair bit, and when I did I loved having a regular running partner. It’s not that I’m undisciplined, but his company nudged me to run just a bit farther or faster than I might on my own. And some days it worked the other way. It’s like we drew motivation and stamina from each other’s presence.

This will come as no surprise to anyone who has ever enlisted a friend to go on a diet or joined a group to quit smoking or drinking. We have this intuitive sense that our minds and bodies are intertwined with those of others, that we can use these deep neural connections to improve discipline and enhance performance. And it often appears to work.

But is there a downside to such psychological cohesion? Is it possible that we might also be emotionally and physically depleted by others’ efforts? In other words, can your self-discipline literally wear me out?

Psychologists are very interested in the power of vicarious thoughts and feelings, because they have clear implications for everything from public health campaigns to personnel management. What if cohesion and camaraderie are actually taking an unseen toll on workers and dieters and recovering addicts?

Yale University psychologist Joshua Ackerman and colleagues decided to explore this idea in the laboratory. They wondered if we might automatically and unconsciously simulate the behavior of others around us—and if such internal aping might lead to real mental exhaustion and breakdown of discipline. They devised a couple clever experiments to test this theory of vicarious depletion.

In one study, they had a group of volunteers read a story about a waiter at a fancy restaurant. The waiter arrives at work hungry, but he is prohibited from eating any of the restaurant food. The story describes in mouth-watering detail the meals that the hungry waiter must serve: Imagine cold poached salmon, roast chicken and fresh asparagus, chocolate mousse cake. Some simply read the story, but others were told to put themselves in the waiter’s shoes, to imagine his thoughts and feelings.

Then all the volunteers played a game sort of like The Price Is Right. They estimated the value of goods like watches and cars and major appliances and bid on them. The idea was to see if vicariously experiencing the waiter’s self-discipline would deplete the volunteers' own self-discipline—and if that depletion would affect their behavior in a completed unrelated realm, namely shopping. Would the torture of denying oneself all that delicious food turn the volunteers into spendthrifts?

And it did, dramatically. Those who suffered along with the fictional waiter spent a full $6000 more than the others on imaginary luxury items. The psychologists did a separate test of mood just to rule out the possibility that they were squandering their cash because of grumpiness. They weren’t. It appears they exhausted their reserve of self-discipline in the restaurant and that the exhaustion carried over.

The psychologists wanted to double-check these findings using a more realistic and complex scenario. Some of the volunteers did the same hungry waiter exercise, but others read about a well-fed waiter who worked in a mediocre fast-food joint. Afterward they had them complete a difficult and time-pressured word problem—one known to tax a host of executive skills like concentration, motivation and information processing.

The results, reported in the March issue of the journal Psychological Science, were interesting and not entirely expected. Again, those who took the part of the hungry waiter became cognitively depleted—leading to inferior performance on the problem-solving task. But those who merely witnessed the waiter’s self-control were better problem-solvers than those who witnessed the well-fed waiter. That is, seeing someone exert control sparked the idea of discipline and reinforced the goal, but actually experiencing the denial led to vicarious exhaustion.

This raises an intriguing possibility. It’s well known that dysfunctional groups don’t perform well, but these findings suggest that group coordination can also work “too well.” That is, if group members—workers, exercisers, addicts—are too tightly synchronized with each other, the exhaustion of one group member can spread to the entire group. Despite its name, self-control is a social enterprise, which means that our own successes and failures may be shaped by others more than we like to think.

For more insights into the quirks of human nature, visit “We’re Only Human” at www.psychologicalscience.org/onlyhuman. Excerpts from the blog also appear regularly in the magazine Scientific American Mind and at http://www.sciam.com/.