Academic social networking sites are important communication tools commonly used by scholars. In order to obtain an understanding of how scholars at US higher education institutions utilize these sites, this study took ResearchGate (RG) as an example and collected data from 168,059 users from 61 US higher education institutions at three research activity levels as defined by the Carnegie Classification. A hierarchical cluster analysis was conducted, and four clusters of institutions with different behavior patterns were observed. The results indicate that US higher education institutions play different roles based on their academic influence in the network and demonstrate distinct behaviors in overall participation, information seeking, and information sharing. Users from universities of higher academic influence exhibited a preponderance for presentation behavior and were popular in the network, while scholars at moderate research-level institutions were active in seeking behavior as well as self-improvement. However, those at lower levels were comparatively inactive. The hierarchical clustering result also suggests that user behavior on this academic social networking site reflects the academic research activity level and level of academic influence accurately and effectively. These findings show a positive correlation between levels of scholarly output and utilization of academic social networking sites. This study also contributes to the ongoing efforts in understanding the scholarly use of academic social networking sites, and to the debate on whether associated alternative metrics (altmetrics) serve as supplementary evaluation measures of scholarship in higher education. The practical implications of the study are also discussed.