LAUSR

Abstract The purpose of this study was to investigate the role of skin conductance level reactivity (SCLR) and respiratory sinus arrhythmia reactivity (RSAR) in preschoolers’ social dominance, as well as potential gender differences in these associations. Reactivity was assessed in response to viewing videos of social exclusion and a post‐aggression discussion. In a community sample of 94 preschool children followed over one calendar year, reactivity to the post‐aggression discussion, but not exclusion, video was related to social dominance. Specifically, increased RSAR to the post‐aggression discussion video was positively associated with concurrent social dominance for both boys and girls. Longitudinally, for boys only, coactivation (i.e., increases in SCLR accompanied by increases in RSAR) to the post‐aggression discussion video, which may reflect dysregulated, emotionally labile reactions to stress, was associated with relatively low levels of social dominance across the course of the year. Overall, findings contribute to a growing literature documenting the role of autonomic reactivity in preschoolers’ social adjustment and extend this work to their capacity to achieve and maintain socially dominant positions with peers.