Knowing what skills underlie college success can allow students, teachers, and universities to identify and to help at-risk students. One skill that may underlie success across a variety of subject areas is structure building, the ability to create mental representations of narratives (Gernsbacher, Varner, & Faust, 1990). We tested if individual differences in structure-building ability predicted success in two college classes: introductory to psychology and introductory biology. In both cases, structure building predicted success. This effect was robust, with structure building explaining variance in course grades even after accounting for high school GPA and SAT scores (in the psychology course) or a measure of domain knowledge (in the biology course). The results support the claim that structure building is an important individual difference, one that is associated with learning in different domains. [This article was published in "Applied Cognitive Psychology," v30 n3 p454-459 May-Jun 2016.]