"I am a lovable person." "Not."

A milestone in the self-help movement was the publication of Norman Vincent Peale’s The Power of Positive Thinking in the early 1950s, which encouraged Americans to both think and talk positively about their lives and themselves. By the mid-1980s, that therapeutic philosophy had become so pervasive in American society that the Saturday Night Live comedian Al Franken wickedly parodied self-glorification through his alter-ego Stuart Smalley, who wrote the quintessential self-help volume: I’m Good Enough, I’m Smart Enough, and Doggone It, People Like Me!

A lot has changed since the 80s. Comedy writer Franken is now the junior Senator from Minnesota, and will soon be writing laws instead of SNL skits. But one thing has not changed appreciably: Americans are still being urged—through self-help books, TV therapists and the like—to think positively and make daily affirmations of their self-worth.

But do they work? Is self-affirmation a sound scientific idea, or just more of our therapeutic culture’s gobbledygook? Interestingly, despite its broad popularity, the effectiveness of positive self-talk has never been rigorously tested. Until now. Psychologist Joanne Wood of the University of Waterloo and her colleagues recently decided to explore the idea in the laboratory. They report their surprising findings in the July issue of the journal Psychological Science.

There’s scientific reason to be skeptical about the value of self-affirmation. Psychologists know, for example, that people have a great deal of difficulty balancing two contradictory ideas. We may try to tell ourselves we’re something we’d like to be, but most of us are deeply resistant to ideas that violate our true sense of identity. Based on this theory, Wood reasoned that forced affirmations might merely remind some people of how they are not measuring up—and indeed might boomerang and make them feel worse. Here’s the experiment:

Wood gave a group of volunteers a standard test for self-esteem, and selected those who scored highest and lowest. Then they all participated in a writing exercise, but half got this instruction: Every time you hear a bell sound, repeat to yourself: “I am a lovable person.” The bell sounded about every 15 seconds during the exercise, and afterward she measured their mood and self-esteem. She also had the volunteers think about the words “I am a lovable person”; but some thought only about why the statement might be true, while others thought about why the statement might be either true or false.

The results were unambiguous and ironic. Those who already felt good about themselves got a slight boost from self-loving talk, but those who had low self-esteem to begin with got worse—more depressed and more self-critical. But interestingly, the volunteers who tried to focus on only positive thoughts about themselves did worse than those who were encouraged to think both good and bad things about themselves. Those preoccupied with self-affirmation were probably unsuccessful at suppressing all negative thinking, giving the negativity more power—power enough to trump the self-loving words.

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