Dimensional comparisons--i.e., comparisons between achievements in different domains--have to date been examined particularly between students' achievements in different school subjects. Numerous studies have documented that dimensional comparisons between mathematical and verbal achievements significantly affect students' mathematical and verbal self-concepts. However, dimensional comparisons also take place and affect self-evaluations in other contexts. The present study is the first to examine indications of dimensional comparisons between faculty members' research and teaching achievements. For this purpose, we extended the reciprocal I/E model, which describes the relations between mathematical and verbal achievements and self-concepts over time, to the domains of research and teaching. We examined our generalized reciprocal I/E model in a sample of 681 faculty members from German universities by considering their research and teaching achievements and self-concepts at four measurement points over two years. Results of cross-lagged analyses indicated positive dimensional comparison effects: The participating faculty members reported higher (lower) research and teaching self-concepts after high (low) achievement not only in the same domain, but also in the other domain. This core finding has important implications for our knowledge of the impact of dimensional comparisons in the formation of domain-specific self-concepts, as well as for the debate about the research-teaching nexus, as it suggests a strong link between research and teaching in terms of self-assessments.