Research on overpraising

Researchers have found that contrary to what some might think, students with low self-esteem can suffer further if they are overpraised. According to the University of Southampton study, praise became "overpraise" when there was an additional word, such as an adverb. For example,"you're good at this" was simple praise, while "you're incredibly good at this" was considered inflated praise. The findings suggested inflated praise could put too much pressure on those with low esteem. 
Brummelman, E., Thomaes, S., Orobio de Castro, B., Overbeek, G., & Bushman, B. J. (in press). “That’s not just beautiful—that’s incredibly beautiful!” The adverse impact of inflated praise on children with low self-esteem. Psychological Science
http://www.independent.co.uk/news/education/education-news/children-with-low-selfesteem-could-be-harmed-if-they-are-lavished-with-too-much-praise-by-parents-study-claims-9039956.html