This paper aims to investigate to what extent a bias in self-evaluation is an enduring characteristic among children, and whether there is a relationship between the trajectory of children's self-evaluation bias over a five-year period and their psychosocial adjustment. 462 children (200 boys) in Grade 3 (mean age=8.6 years old) or Grade 4 (mean age=9.7 years old) at the outset of the study participated following their parents' written consent. The group-based approach using a multinomial modeling strategy allowed identifying five groups based on changes in the children's self-evaluation bias over the five-year period. Children in the stable and highly positive bias group stood out as having markedly more positive scores on all indices of psychosocial adjustment, and also outperformed the other children in achievement in language arts and math. (Contains 3 tables and 1 figure.)