Despite academics' enthusiasm about the concept of grit (defined as consistency of interest and perseverance of effort), its benefit for academic achievement has recently been challenged. Drawing from a longitudinal sample (N = 2018; 55.3% female; sixth-nineth grades) from Finland, this study first aimed to investigate and replicate the association between grit and achievement outcomes (i.e., academic achievement and engagement). Further, the present study examined whether growth mindset and goal commitment impacted grit and whether grit acted as a mediator between growth mindset, goal commitment, and achievement outcomes. The results showed that the perseverance facet of grit in the eighth grade was associated with school achievement and engagement in the nineth grade, after controlling for students' conscientiousness, academic persistence, prior achievement and engagement, gender and SES, although the effect on engagement was stronger than on achievement. In addition, grit was predicted by goal commitment in the sixth grade, but not by the growth mindset in the sixth grade. Finally, the perseverance of effort (not the consistency of interest) mediated the effect of goal commitment on engagement. These findings suggest that grit is associated with increased engagement and academic achievement; and practitioners who wish to improve grit of adolescents may encourage goal commitment more than growth mindset.
Keywords: Engagement; GPA; Goal commitment; Grit; Growth mindset; Longitudinal data.