Fluid Intelligence and Competence Development in Secondary Schooling: No Evidence for a Moderating Role of Conscientiousness

Abstract

Fluid intelligence and conscientiousness are important predictors of students’ academic performance and competence gains. Although their individual contributions have been widely acknowledged, less is known about their potential interplay. Do students profit disproportionately from being both smart and conscientious? We addressed this question using longitudinal data from two large student samples of the German National Educational Panel Study. In the first sample, we analyzed reading and mathematics competencies of 3778 fourth graders (Mage = 9.29, 51% female) and gains therein until grade 7. In the second sample, we analyzed the same competencies in 4942 seventh graders (Mage = 12.49, 49% female) and gains therein until grade 9. The results of (moderated) latent change score models supported fluid intelligence as the most consistent predictor of competence levels and gains, whereas conscientiousness predicted initial competence levels in mathematics and reading as well as gains in mathematics (but not reading) only in the older sample. There was no evidence for interaction effects between fluid intelligence and conscientiousness. We found only one statistically significant synergistic interaction in the older sample for gains in reading competence, which disappeared when including covariates. Although our findings point to largely independent effects of fluid intelligence and conscientiousness on competence gains, we delineate avenues for future research to illuminate their potential interplay.

Data from the National Educational Panel Study (NEPS) in Germany: Educational Pathways of Students in Grade 5 and Higher

“…Furthermore, a relevant topic concerns the question of how individual prerequisites shape the development of competences. The papers addressing this issue based on data from NEPS SC3 included cognitive (reasoning ability; Brandt & Lechner, 2022) or motivational predictors (Miyamoto et al, 2018(Miyamoto et al, , 2019, social behavior (prosocial behavior and peer problems; DeVries et al, 2021;life satisfaction;Lettau, 2021;Rathmann et al, 2018), personality traits (conscientiousness; Brandt & Lechner, 2022;Lechner et al, 2019) or gender-role orientation (Ehrtmann & Wolter, 2018) in order to explain competence levels and competence gains in secondary school students. For instance, Brandt and Lechner (2022) showed that reasoning ability as an indicator of fluid intelligence predicted the level and gains in reading and mathematical competences, whereas conscientiousness showed only small independent effects on competences.…”

“…In addition to analyzing the main effects of different predictors, the data also allowed for investigating interaction or mediating effects (e.g., Brandt & Lechner, 2022;Miyamoto et al, 2019) which, given the large number of constructs captured, gives multiple options for analysis that go beyond the available work.…”

“…From a methodological perspective, a variety of approaches can be applied to analyse the data, especially those that require longitudinal data. Studies based on NEPS SC3 data, for example, used growth curve modeling (e.g., Herke et al, 2019), different cross-lagged panel models (e.g., Gnambs & Lockl, 2022;Kleinkorres et al, 2020), latent change score models (e.g., Brandt & Lechner, 2022) or latent growth mixture models (Freund et al, 2021).…”

Is There Evidence for Intelligence-by-Conscientiousness Interaction in the Prediction of Change in School Grades from Age 11 to 15 Years?

“…Apart from the impressive evidence for the unique contributions of fluid intelligence and conscientiousness in predicting success in school, these two factors may also interact meaningfully. Indeed, some studies have shown that intelligence and personality interact in the prediction of educational achievement (e.g., Bergold and Steinmayr 2018 ), whereas others could not find such an effect ( Brandt and Lechner 2022 ; Zhang and Ziegler 2015 ). In addition, different lines of reasoning argue for two distinct interaction processes.…”

“…To our knowledge, to date no study has investigated the potential longitudinal effects of intelligence-by-conscientiousness interactions on school grades, a highly relevant indicator of academic achievement, and could thus not model a potential interaction effect on the development of educational success. The majority of existing research also focuses on older students, using samples stemming from older adolescents or young adults from upper high school or university (but see, e.g., Brandt and Lechner 2022 ). The predictive value of intelligence, personality, and their interaction might be different in younger samples with a more diverse education background.…”