Just to be clear, Wood et al (2009) summarise their propositions on page 861:
Thus, we propose that positive self-statements have the potential to
make one feel worse if they lie outside one’s latitude of acceptance,
are self-discrepant and thereby highlight one’s failures to meet one’s
standards, and arouse self-verification motives. We further propose
that positive self-statements are especially likely to backfire for
the very people they are meant to benefit: people with low
self-esteem. Such people, by definition, see themselves as failing to
meet standards in more domains or in more important domains than do
people with high self-esteem. Moreover, self-verification motives
should bias people with low self-esteem to reject positive
self-statements, but encourage people with high self-esteem to
accept them.
In the literature review, Wood et al cite several articles related to attitude formation and self-relevant feedback. They mention one particular study, where
Eisenstadt and Leippe (1994) asked participants to identify a trait
they would like to possess but believed they lacked. When Eisenstadt
and Leippe later told participants that they actually did possess that
ideal trait, participants felt worse, rather than better.
References
- Eisenstadt, D., & Leippe, M.R. (1994). The self-comparison process
and self-discrepant feedback: Consequences of learning you are
what you thought you were not. Journal of Personality and Social
Psychology, 67, 611–626.
- Wood, J., Elaine Perunovic, W., & Lee, J. (2009). Positive Self-Statements: Power for Some, Peril for Others Psychological Science DOI: 10.1111/j.1467-9280.2009.02370.x