Big-fish–little-pond effect (BFLPE) is a frame of reference model introduced by Herbert W. Marsh and John W. Parker in 1984. Marsh and Parker argued that individuals compare their own self-concept with their peers and that equally capable individuals have higher self-concepts when in a less capable group than in a more capable group.
The BFLPE hypothesizes that it is better for academic self-concept to be a big fish in a little pond (gifted student in regular reference group) than to be a small fish in a big pond (gifted student in gifted reference group). Research evidence for the big-fish-little-pond effect (BFLPE) has demonstrated that attending high-ability schools has a negative effect on academic self-concept.
It was publicized by Malcolm Gladwell in his book David and Goliath: Underdogs, Misfits, and the Art of Battling Giants.