A longitudinal multilevel model analysis of the within-person and between-person effect of effortful engagement and academic self-efficacy on academic performance.

Using data from an accelerated longitudinal study, we examined the within-person and between-person effect of effortful engagement and academic self-efficacy on academic performance across students (N=135) in elementary school. Teachers assessed participants' effortful engagement and participants rated their academic self-efficacy once per year for 3 years. Academic performance was assessed through standardized test scores in reading and math. Multilevel models indicated that within-person change in Effortful Engagement and Academic Self-Efficacy scores significantly predicted concomitant within-person change in reading test scores, B=2.71, p=.043, Pseudo-R2=.02 and B=4.72, p=.005, Pseudo-R2=.04, respectively. Participants with higher between-person levels of Effortful Engagement had higher initial reading test scores, B=10.03, p=.001, Pseudo-R2=.09, and math test scores, B=11.20, p<.001, Pseudo-R2=.15, whereas participants with higher between-person levels of Academic Self-Efficacy showed a faster rate of increase in math test scores across elementary school, B=10.21, p=.036, Pseudo-R2=.25. At the between-person level, Effortful Engagement mediated the association between Academic Self-Efficacy and both reading and math test scores, although no support was found for mediation at the within-person level. Collectively, results suggest that trait-level psychological factors can vary meaningfully within school-aged children and that both within-person change and between-person individual differences in these traits have important consequences for academic performance.