Effects of variations in parents’ control styles, especially the amount of power assertion they deploy, have long been a central question in socialization research. Although severe, harsh control is unanimously considered harmful, research on effects of far more common low-to-moderate power assertion is inconsistent. Drawing from attachment and social cognition traditions, we examined whether children’s representations of parents (Internal Working Models, IWMs) moderated associations between parental power assertion and children’s socialization (violating or embracing rules and values, responsiveness to parents). In two studies of community families (Family Study, FS, N = 102, and Children and Parents Study, CAPS, N = 200), employing observations and reports, we assessed parental power assertion at age 4.5, children’s IWMs at ages 8 in FS and 4.5 in CAPS, and socialization outcomes at ages 10 and 12 in FS and 4.5 in CAPS. In FS, children’s IWMs of the parent moderated effects of parental power assertion on socialization outcomes in mother- and father-child dyads (βs = 0.47, 0.41, respectively): Power assertion had detrimental effects only for children with negative IWMs of their parents. In CAPS, findings were replicated for mother-child dyads (β = 0.24). We highlight origins of multifinality in socialization sequelae of parental control.