Moffints (1993) taxonomy of adolescence-limited and life-course-persistent offenders suggests, among other things, that an early onset of antisocial behavior a) increases the likelihood of a life- course persistent offending trajectory and b) is the product of neuropsychological deficits and familial risk factors working in concert. Over two decades of research has yielded a substantial amount of support for Moffitt's claims. Nevertheless, research has yet to significantly expand the repertoire of hiosocial processes that might influence the onset of antisocial behavior during childhood. For instance, only a handful of criminologists have considered the role that infant and early childhood nutrition might play in the development of antisocial behavior. Moreover, studies employing genetically sensitive methods to examine the link between nutrition and child antisocial behavior are virtually nonexistent. Scholars have also neglected to consider the socioemotional mediators of the nutrition-externalizing, relationship, as well as whether infants and children are differentially sensitive to nutritional intake depending on their level of genetic risk, perinatal risk, and security of attachment. Finally, researchers have vet to explore the ways in which nutritional factors across infancy and early childhood work together to influence externalizing behavior. This dissertation seeks to address these gaps in the literature by employing a large, nationally representative sample of twin pairs. The findings suggest that, even after accounting for the influence of genes and the shared ens irocument, nutritional factors Juring infancy and early childhood have both direct and indirect effects on externalizing behavior during kindergarten Furthermore, significant interactions between genetic and nutritional factors, as well as nutritional factors across life stages, were detected. The limitations. of the study are noted and recommendations for policy, theory, and future research are discussed.