How Full Is That Glass, Really?

Apositive outlook--belief in your own future--is a trait associated with greater resilience. But who has got a firmer grip on reality: the glass-half-full optimist or the cold-eyed pessimist who focuses on obstacles ahead?

That's what psychologists Lauren Alloy and Lyn Abramson set out to find in the late 1970s when they began a seminal series of experiments exploring how mood affects the way people think. Back then most therapists took the Freudian view that depressed people--and by extension, pessimists--were out of touch with reality. It made sense, since depression was considered an aberrant mental state. Their work and subsequent research show that the relationship between cognition and mood is far more complex.

In carefully designed experiments, Alloy, then at Northwestern University, and Abramson, then at the State University of New York at Stony Brook, sat students in front of a panel featuring a green light and a button that they were told would activate the light when pressed. In fact, the amount of control students had over the light varied from 0% to 100%, with many points in between. When they were asked how much control they thought they had over the light, the answers surprised the psychologists. Optimistic types (who scored low on tests for depressive symptoms) consistently overestimated their influence. By a lot. On average they believed they had 60% control even in sessions in which their button pressing had purely random effects. "The nondepressed had an illusion of control when in fact they had none," says Alloy. By contrast, more pessimistic students (those who had more depressive symptoms) judged their performance more accurately.

The finding that depressive types were "sadder but wiser," as the researchers put it, rocked conventional thinking in psychology. "Our demonstration was provocative because it was counter to theories of psychopathology," Abramson says. Clearly, nondepressed individuals were just as capable of distorting reality as the mentally ill were supposed to be.

In a second series of experiments with the light panel, the researchers tried to prove that mood really was the deciding factor in how students performed. To do so, they induced a depressed mood in nondepressed students by asking them to read a series of increasingly negative statements, beginning with a neutral idea such as "Today is neither better nor worse than any other day" and ending up with "I'd like to go to sleep and never wake up again." Similarly, they lifted the mood of depressed students by having them read positive statements. Sure enough, the students who were artificially "depressed" made more accurate judgments about their control over the light than students whose mood was happified. "Basically, we could flip the entire phenomenon around," says Alloy.

Were happier folks deluded only about their power to control, or did they have similar illusions about other people? Alloy and Abramson tested that and found that happy people were much more accurate when observing others performing the light-panel task. The result was the opposite, however, with depressed people, who tended to overrate other people's performance. "That fits the theory that depressed people have a poor view of themselves but a better view of others," says Abramson.