Canadian researchers found those with low self-esteem actually felt worse after repeating positive statements about themselves.
They found that, paradoxically, those with low self-esteem were in a better mood when they were allowed to have negative thoughts than when they were asked to focus exclusively on affirmative thoughts.
Writing in the journal, the researchers suggest that, like overly positive praise, unreasonably positive self-statements, such as "I accept myself completely," can provoke contradictory thoughts in individuals with low self-esteem.
Such negative thoughts can overwhelm the positive thoughts.