Executive functions (EFs) refer to a set of diverse, higherorder cognitive skills that includes inhibitory control, cognitive flexibility, updating information in working memory, error monitoring, sustaining attention, and planning. EFs support goal-directed behavior and are believed to play a crucial role in self-regulation of behavior and emotions. It should, therefore, be no surprise that EFs are related to outcomes in diverse domains of functioning that include psychopathology, physical health, academic achievement, career success, and close relationships (Diamond 2013).Because of their importance for Bsuccess in life,^EFs (and self-regulation as a broader construct) have become a major topic of research. EFs have been of particular interest because a number of studies indicate that they are malleable: family and school based interventions have both shown promise for improving EFs, particularly for children with lower initial skills (Blair and Raver 2014;Diamond and Lee 2011;Schmitt et al. 2015). A large body of research has shown that EFs are consistent correlates of externalizing symptoms among both children and adults (Ogilvie et al. 2011;Schoemaker et al. 2013). Given the robust association between EFs and externalizing symptoms and the high societal costs of externalizing psychopathology, EFs have emerged as a promising target for prevention efforts.To fulfill this promise, however, researchers need to move beyond merely documenting associations between EFs and externalizing symptoms. We have reached a point where more nuanced questions are needed to advance the field. For example, how much do EFs contribute to change in externalizing symptoms over time? Despite high rates of cooccurrence among externalizing disorders (Krueger and Markon 2006), are EFs more strongly related to certain types of externalizing disorders? If so, why? What mediating mechanisms can account for the relations between EFs and externalizing symptoms? Answering these questions is necessary for designing effective prevention and treatment programs. The papers in this special section help move us towards this goal by addressing questions about the mediators, moderators, and prediction of longitudinal change for the relations between EFs and externalizing symptoms.As previously noted, EFs are positively related to success in many different domains of functioning. Yet as research on EFs has matured, investigators have adopted a greater focus on specificity, splitting the larger constructs into subdomains. For example, meta-analytic studies suggest that inhibitory control is more strongly related to math than to reading performance (Allan et al. 2014), whereas the relation between cognitive flexibility and these two academic subdomains does not appear to differ (Yeniad et al. 2013). In this special section, Huang-Pollock et al. (2017) and Lonigan et al. (2017) both investigate questions about the degree to which EFs are associated with externalizing symptoms Bin general^as well as specific subtypes of externalizing symptoms such as ina...