Big-fish–little-pond effect (BFLPE) is a term introduced by Herbert W. Marsh, and popularized by Matthew Gardner and Malcolm Gladwell in his bestselling book David and Goliath: Underdogs, Misfits, and the Art of Battling Giants. BFLPE hypothesizes that the self-concept of students is negatively correlated with the ability of their peers in school: Thus, academic self-concepts depend not only on one's academic accomplishments but also the accomplishments of those in the school that a student attends.
An implication of this effect is that low- or medium-ability students might prefer to attend a low-ability school instead of a high-ability school, as this would be better for their self-concept. These pupils can receive additional motivation from low- or medium-ability pupils in their class because their own achievements appear more significant. They feel more honored and may be motivated to keep their edge over the other pupils. This is especially true for pupils with a lack of self-confidence. Some parents send their children, with the explicit recommendation of psychologists, to schools that are known for a moderate level of proficiency.