Empirical study Adolescents’ autonomous functioning and implicit theories of ability as predictors of their school achievement and week-to-week study regulation and well-being Athanasios Mouratidis a,⇑ , Aikaterini Michou b , Aikaterini Vassiou c a Department of Psychology, Hacettepe University, Beytepe Campus 06800, Ankara, Turkey b Graduate School of Education, Bilkent University, 06800 Bilkent, Ankara, Turkey c Department of Primary Education, University of Thessaly, Volos, Greece article info Article history: Available online xxxx Keywords: Motivation Implicit theories Self-determination Academic achievement Students Diary study abstract Research on students’ motivation has mainly focused on interpersonal differences rather than on the ongoing, intrapersonal dynamics that forge students’ everyday life. In this five-month longitudinal (diary) study, we recruited a sample of 179 high school students from Greece (35.8% males; M age = 16.27; SD = 1.02) to investigate through multilevel analyses the ongoing dynamics of students’ motivation. We did so by examining the relation between autonomous functioning and aspects of study regulation (namely, study efforts and procrastination) and well-being (namely, subjective vitality and depressive feelings). After controlling for perceived competence, we found week-to-week autonomous functioning to relate positively to study efforts and subjective vitality and negatively to procrastination and depres- sive feelings. Interestingly, implicit theories of ability - the degree to which one believes that ability is fixed or amenable - were found to moderate the week-to-week relations of autonomous functioning to study efforts and homework procrastination. In particular, autonomous functioning co-varied positively to study efforts and negatively to homework procrastination only among students who believed that abil- ity is malleable. Also, beliefs that ability is fixed predicted poorer grades, lower mean levels of study efforts, and higher homework procrastination. The results underscore the necessity of taking a more dynamic view when studying motivational phenomena and the importance of jointly considering the implicit theory framework and self-determination theory. Ó 2016 Elsevier Inc. All rights reserved. 1. Introduction Students experience several ups and downs within a school year. At times they may be fully committed to do their homework and experience higher well-being while at other times they may tend to procrastinate their homework and feel despondent. The issue of week-to-week fluctuation of students’ study regulation and well-being has received far less attention compared to the research question of why some students, on average, better regu- late their study behavior and affect than others. This is an impor- tant oversight because investigating the intrapersonal fluctuations of students’ motivational processes and outcomes in conjunction with the interpersonal differences can help us better comprehend the ongoing dynamics that students experience in their everyday lives. Other things being equal, we propose that students’ intraper- sonal fluctuation of study regulation and well-being corresponds to a respective fluctuation of autonomous functioning (as reflected by students’ awareness of self, which we consider an important element of people’s disposition for autonomous functioning - see Weinstein, Przybylski, & Ryan, 2013). Specifically, we aimed to investigate to what extent the week-to-week fluctuation of stu- dents’ autonomous functioning co-varies with two markers of study regulation (i.e., study efforts and homework procrastination) and two markers of well-being (i.e., subjective vitality and depres- sive feelings). Further, we examined whether this co-variation differs among students who differ in implicit theories they hold about ability. Implicit theories refer to the beliefs that students hold about the nature of the ability; that is, whether ability is a fixed trait or can be developed through effort and practice (Dweck, 1999). By focus- ing on implicit theories, we aimed to test whether such ability beliefs moderate the week-to-week associations of autonomous functioning to study regulation and perhaps to well-being. In doing http://dx.doi.org/10.1016/j.cedpsych.2016.09.001 0361-476X/Ó 2016 Elsevier Inc. All rights reserved. ⇑ Corresponding author. E-mail addresses: athanasios@hacettepe.edu.tr (A. Mouratidis), aliki.michou@ bilkent.edu.tr (A. Michou), ekvasiou@uth.gr (A. Vassiou). Contemporary Educational Psychology xxx (2016) xxx–xxx Contents lists available at ScienceDirect Contemporary Educational Psychology journal homepage: www.elsevier.com/locate/cedpsych Please cite this article in press as: Mouratidis, A., et al. Adolescents’ autonomous functioning and implicit theories of ability as predictors of their school achievement and week-to-week study regulation and well-being. Contemporary Educational Psychology (2016), http://dx.doi.org/10.1016/j. cedpsych.2016.09.001