Purpose: A massive literature documents the positive association between poverty-related cumulative risk and children’s maladjustment,but little is known about the mediating and moderating mechanisms underlying this relation.We examined whether maternal responsiveness mediated the longitudinal relation between cumulative risk and learned helplessness in adolescence,and whether this mediating process was moderated by children’s difficult temperament.Methods: We used data from a three-wave prospective longitudinal study (with assessments 4 years apart) of 278 rural,white mothers and their adolescent children.Cumulative risk was based on nine risk factors (wave 1),maternal responsiveness was based on observer ratings and child report,difficult temperament was based on maternal report,learned helplessness was based on a behavioral task.Results: After controlling for gender,initial maternal responsiveness and learned helplessness,childhood cumulative risk significantly contributed to learned helplessness in adolescents.This association was partially mediated by maternal responsiveness.Moreover,difficult temperament moderated the mediated path through maternal responsiveness,such that this indirect effect was much stronger for children with normal temperament than for those with difficult temperament.Conclusions: These findings underscore the importance of integrating family stress model and organism-environment interaction model to understand how and when cumulative risk impacts children’s development.