A thorough understanding of how social relationships contribute to child and adolescent trajectories for antisocial behavior may be facilitated by: (a) ascertaining multiple relationship processes (e.g., warmth and reciprocity, coercion and deviancy training); (b) focusing on multiple relationships (e.g., with parents, peers, siblings, and teachers); and (c) assessing relationship processes using increasingly sophisticated measurement and theoretical models (e.g., global ratings and sequential and dynamical systems analyses) of observed microsocial interaction. The reports comprising this special issue, and how they build on and advance previous research efforts, are described from this frame of reference.