Growing evidence has suggested that the mechanisms underlying the 3 dimensions of psychopathic traits, including grandiose-manipulative, callous-unemotional, and daring-impulsive, are different. As yet, the neurobiological correlates of each dimension have not been fully understood. In this study, we examined if reward processing deficits were differentially associated with these traits, and whether social adversity moderated these relationships. Pre-ejection period (PEP) was assessed in children between 8 and 10 years of age from the community (N = 340, Mage = 9.06, SD = .60; 48.2% boys) while they were completing a reward task, and the caregivers rated children's psychopathic traits. Results indicated that (a) high callous-unemotional traits were associated with less PEP shortening, reflecting reward hyporesponsivity, at low levels of social adversity, and more PEP shortening, indicating hyperresponsivity, at high levels of social adversity, (b) high daring-impulsive traits were associated with hyperresponsivity at low levels of adversity only, and (c) grandiose-manipulative traits were not linked to reward processing deficits. Findings provide further evidence that different etiologies may underlie various dimensions of psychopathic traits and highlight the important role of psychosocial factors in understanding the neurobiological mechanism of youth psychopathy. (PsycInfo Database Record (c) 2021 APA, all rights reserved).