“Subjects were given differing degrees of control over the lighting of a light. For some, the action they took perfectly controlled the light: It went on every time they pressed a button, and it never went on if they didn’t press it. The others, though, had no control whatsoever: The light went on regardless of whether or not they pressed the button; they were helpless.

The people in both groups were asked to judge, as accurately as they could, how much control they had. Depressed people were very accurate. When they had control, they assessed it accurately, and when they did not have control, they said so. The nondepressed people were accurate when they had control but when they were helpless, they undeterred - they still judged that they had a great deal of control. The depressed people knew the truth. The nondepressed people had benign illusions that they were helpless when they actually were.

Money was added. When the light went on, the participants won money. But the benign illusions of nondepressed people did not go away; in fact, they increased. Under one condition, where everyone had some control, the task was rigged so that everyone lost money. Here, nondepressed people said they had less control than they actually had. When the task was rigged so that everyone won money, nondepressed people said they had more control than they actually had. Depressed people on the other hand, were rock solid, accurate whether they won or lost.

Supportin evidence confirms that depressed people are accurate judges of how much skill they have, whereas nondepressed people are think they are much more skillful than others judge them to be. Nondepressed people remember more good events than actually happened, and they forget the bad events. Depressed people are accurate about both. Nondepressed people believe that if it was a success, they did it, it is going to last, and moreover, that they are good at everything; but if it was a failure, someone did it to them, it is going away quickly, and it was just this one little thing. Depressed people are evenhanded about success and failure.”

“In a follow up study, it was founded that nondepressed people who are realists go on to become depressed at a higher rate than nondepressed people who have these illusions of control. Realism doesn’t just coexist with depression, it is a risk factor for depression.”

Martin E.P. Seligman, PH.D.