Antisocial behavior is multifaceted and has a rich history ofresearch. Nearly two decades have passed since RichtersandCicchetti (1993a)co-editedaSpecialIssueinthisJournalentitled, “Toward a Developmental Perspective on ConductDisorder.” At that time, researchers in the field examinedquestionssuchastheutilityoftaxonomiesindefiningantiso-cial behavior (Hinshaw, Lahey, & Hart, 1993; Richters C Pennington & Bennetto,1993), gender differences in antisocial behavior (Zahn-Wax-ler, 1993; Zoccolillo, 1993) and the role of attachment andfamilies in the etiology of antisocial behavior (Greenberg,Speltz, & Deklyn, 1993; Waters, Posada, Crowell, & Keng-Ling, 1993). The issue ended by presenting some fresh ap-proaches to the treatment of antisocial behavior in youth(Dodge, 1993; Kazdin, 1993). At the time of publication,these manuscripts contributed a great deal to the literatureon antisocial behavior, propelling the field forward intonew and exciting directions.MuchhaschangedsincethepublicationofthatSpecialIs-sue. Advances in quantitative theory and practice have madeit increasingly possible to account for heterogeneity withinthose who exhibit antisocial behavior using person-centeredanalyses and growth curve analyses (Nagin, 1999, 2005).We now have a greater understanding of the varied develop-mental pathways by which youth come to exhibit antisocialbehavior (Campbell et al., 2010; Mulvey et al., 2010). How-ever,thisliteratureisrelativelynew,andmoreworkisneededin order to understand the variability in the development ofantisocial behavior.Researchershavealsobeguntoincorporatemultiplelevelsof analysis in their approach to studying antisocial behavior,particularly the intersection of biological and environmentalinfluences on antisocial behavior (Cicchetti, 2008). Wenow understand that genetic vulnerabilities for violencemay be moderated by extreme environmental events, suchas childhood maltreatment (Caspi et al., 2002; Jaffe et al.,2004; Kim-Cohen et al., 2006; Mead, Beauchaine, & Shan-non, 2010). The literature has moved toward understandinghow distinct physiological patterns, such as low resting heartrate, may help us to further understand differences in risk forantisocial behavior (Baker et al., 2009). In this issue, authorsbuild upon the existing research to apply a multilevel ap-proach toward understanding antisocial behavior acrossmany developmental periods, using a number of differentphenotypic expressions of antisocial behavior (e.g., aggres-sion, substance use).As the field has become more multidimensional, modelsof how antisocial behavior develops have also becomemore comprehensive and innovative. Cascade approacheshave highlighted the dynamic role of early experience in in-fluencing later outcomes (Cicchetti & Tucker, 1994; Masten& Cicchetti, 2010). Such approaches have been combinedwith existing models to investigate how early risk factorsmay impact functioning across multiple domains and levelsof analysis to influence antisocial behavior. Studies have ex-aminedhowearlyexperiencesshapebraindevelopment,neu-rotransmitter functioning, temperament, and neuroendocrinefunctioning, which may in turn influence antisocial behavior(Cicchetti, 2002; Gunnar & Vazquez, 2006; Mead et al.,2010). The role of gender, attachment, and parent–child rela-tionships can now be examined within broader contextualmodels of antisocial behavior. The articles in this issue shareaninnovativespiritandtestnoveltheoriesamongpopulationsat varying levels of risk from young childhood to samples ofincarcerated offenders.