In their excellent review of the environmental and genetic underpinnings of personality disorders, Turner, Prud’homme, and Legg (this volume) provide compelling evidence that early family adversity (e.g., maltreatment, parenting difficulties, parental separation) is an environmental risk factor for offspring personality difficulties. However, little is known about how and why these family characteristics increase the risk for various personality disorders. Guided by evolutionary theory, the goal of this commentary is to illustrate how the synthesis of these two areas of inquiry may advance an understanding of the origins and course of typical and atypical personality characteristics in mutually informative ways. First, building on the coverage of attachment in the primary chapter, the authors address how other behavioral systems that are designed to defend against social threat and acquire resources may mediate the distinct personality sequelae experienced by children exposed to family adversity. Second, in identifying sources of heterogeneity in family risk, the authors highlight the value of expanding the conceptualization of moderators beyond diathesis-stress models. Consistent with differential susceptibility theory, they describe how temperamental, physiological, and genetic moderators may serve to heighten sensitivity to supportive as well as adverse family conditions rather than simply acting as diatheses that selective sensitize individuals to harsh socialization contexts.