Same same but different: The role of subjective domain similarity in the longitudinal interplay among achievement and self-concept in multiple academic domains.

The present study examined the associations between grades and self-concept within and between four academic domains from an intraindividual perspective. Further, we explored whether students' subjective domain similarity moderated intraindividual between-domain effects of achievement on self-concept and vice versa. A sample of 756 Swiss high-school students reported on their academic self-concept in mathematics, German (native), English, and French on three measurement occasions across high school. Students reported on the subjective domain similarity. School administrators reported students' grades. Achievement in one domain had a positive effect on self-concept within the same domain and a negative effect on cuncurrent and later self-concept in other domains. Conversely, self-concept in one domain had a positive effect on achievement in the same domain and a negative effect on cuncurrent and later achievement in other domains. Further, subjective domain similarity attenuated the negative effect of achievement in one domain on self-concepts in another domain on the same measurement occasions. However, subjective domain similarity was not found to moderate the effect of achievement in one domain on change in self-concepts in another domain or vice versa. Public significance statement: Academic achievement leads to a better academic self-concept within a given domain (e.g., mathematics) and vice-versa. However, higher achievement in one domain (e.g., mathematics) can lead to worse self-concept in another domain (e.g., first language). The present study shows that between domain effects of achievement on self-concept might be more pronounced if the student that is evaluating her/his self-concept in the two domains perceives the two domains at hand as different rather than similar. Accordingly, teachers might want to make the similarities and links between different academic domains more visible to students to avoid negative effects of positive feedback in one domain on self-concept in other domains.