In a 10-year study of 400 fifth-graders, psychologist David Dweck found that kids who were praised for being smart were more likely to give up, lack confidence and be afraid to take risks  When she repeated the experiment at different social stages, she found the same results for both men and women
The study found that praise had the greatest effect on the cleverest girls, who mostly collapsed in a test of failure responses.
 Even preschoolers are not immune to the negative effects of praise