The big-fish–little-pond effect on academic self-concept: The moderating role of differentiated instruction and individual achievement

• Class average achievement is negatively related to French self-concept (FSC).
• Differentiated instruction strategies do not attenuate the BFLPE.
• BFLPE exists when individual achievement and differentiated instructions are low.

The big-fish–little-pond effect (BFLPE) postulates that class-average achievement has a negative effect on students' academic self-concept. We hypothesized that teachers' use of differentiated instruction strategies would attenuate the BFLPE on French self-concept (FSC). We also explored whether this moderation effect depended on children's individual achievement (i.e., a three-way interaction among class-average achievement, individual achievement, and differentiated instruction). Using hierarchical linear modeling, we tested this moderation effect in a sample of 422 elementary students nested in 27 classrooms. The results showed that the three-way interaction was significant. Simple slopes indicated a significant BFLPE only for students with low individual achievement and for whom teachers reported less frequent use of differentiated instruction strategies. Our findings provide insights into which students may be the most affected by the BFLPE and which teaching practices can attenuate its negative consequences on students' FSC. We discuss results in relation to the literature on the BFLPE and on differentiated instruction.