The studies included in this special issue on gene-peer interplay in child and adolescent outcomes can uniformly be described as cutting edge and methodologically sophisticated. When viewed together, they all but conclusively document the presence and importance of gene-peer interplay in child and adolescent outcomes. Nevertheless, more work on the topic is needed, both because the inherent complexity of peer studies means we know less on this topic than on many others, but also because available research is limited by the descriptive nature of the findings. The current commentary offers suggestions for future work that would begin to remedy these limitations.