Proactive and reactive aggression subtypes are distinguishable as early as the preschool years. However, their early physiological and social–emotional correlates have not been examined simultaneously. We tested whether children’s skin conductance level, anger regulation, and trust in others were differentially related to their proactive and reactive aggression. Four‐year‐olds and their primary caregivers were recruited from a large Canadian city (N = 150). Controlling for reactive aggression,… |