This research explored the relationship between a set of variables, such as reading comprehension and logical-mathematical intelligence, along with two sets of cognitive and learning variables, in respect to overall school performance and school performance in the subject of Spanish Language in a population of socially vulnerable secondary school students (N=688). The main objective of this study was to examine the differences and quantify the effect of the addition of the above-mentioned variables to an explanatory model for academic performance. For this purpose, comparative analysis, bivariate correlation and stepwise multiple regression models were used. The results showed that 34.9% of the variance of students' grade point average in the subject of Spanish Language could be explained by the variables that were added to the model. The positive effect of reading comprehension, achievement attributed to effort, and the self-regulation strategy of revision stood out in this model. At the same time, a negative effect was found for older age and attributing achievement to external causes. In addition, the explanatory model introduced in this article showed greater predictive power for the female group; notably the variable critical comprehension also had a positive effect for the female group. Finally, the main educational implications for these findings are analyzed and discussed in this paper. [ABSTRACT FROM AUTHOR]