Combining complete social networks and structural equation modeling, we investigate how two learning-related cognitions, academic self-efficacy and growth mindsets, relate to integration in support networks of 580 university students in 30 seminar groups. We assessed integration as popularity in academic support networks (being an academic helper and collaborator) and in social support networks (being a friend and resource for sharing personal difficulties). Perceived integration in both networks was measured with self-reports, whereas actual integration in both networks was measured with sociometric peer-reports. Structural equation modeling showed that students who were initially more integrated in academic support networks became more integrated in social support networks over time, but not vice versa. Students with higher academic self-efficacy perceived themselves to be an academic resource for others, which in turn enhanced peer-reported academic integration. Academic self-efficacy was related to growth mindsets and growth mindsets were related to actual integration in academic support networks.