Comparing the effects of intelligence, learning strategies, and HEXACO personality traits on high school academic achievement

Numerous studies have shown that general cognitive ability, learning strategies, and personality traits are consistent predictors of academic achievement. Although some meta-analyses have compared the strengths of their effects, very few studies have directly compared them within the same sample. For this reason, our study aimed to determine the unique and incremental effects of each of these components while controlling for gender effects. The sample consisted of 228 high school students (103 females, 45.0%). General cognitive ability was assessed using 15 selected items from the ICAR Progressive Matrices test (Condon & Revelle, 2014). For self-assessment of the frequency of using learning strategies, we used 11 items from the Banja Luka Inventory of Learning Strategies (Lakić et al., 2015) for strategies which our previous research identified as effective. HEXACO personality traits were assessed using the BHI questionnaire (de Vries, 2013). As expected, girls had higher average grades, and individually, general cognitive ability was by far the strongest correlate of grades. After controlling for the effects of gender and intelligence, and using Bayesian model averaging to select preferred models, we observed that the incremental contribution of the five selected learning strategies was above 10%, while it was negligible for personality traits. In addition to replicating findings on the importance of general cognitive ability, our study shows that certain learning strategies contribute to academic achievement independently of intelligence, and that the effect of personality traits is likely indirect and significantly weaker. In the discussion, we emphasize the need for teaching effective learning strategies.