This document presents the main findings of the research carried out in the research group of Cognitive Styles from the Universidad Pedagógica Nacional about the effects of the cooperative learning methodology in academic achievements and socials skills in relationship to cognitive style, in primary and high school students of several teaching institutions. Regarding academic achievements, the studies have shown positive effects of cooperative learning methodology in comparison to individualistic ones; those effects are statistically relevant, specifically in the math area, rather than for lower grades students. Concerning social skills, the findings are not statistically significant, but they do contribute to a better understanding of the processes that take place when applying cooperative learning. Finally, regarding the cognitive style variable, the results are inconclusive because both stylistic polarities are beneficial to this methodology.