“…As mentioned, the Dual Failure Model (Patterson & Capaldi, 1990) proposes that the association between externalizing problems and further internalizing problems via failures in two key developmental processes takes place in the elementary school period. The developmental nature of these processes highlights the importance of testing the model in the first years of elementary school, which was not the case in many of the studies cited (e.g., Klostermann et al, 2016;Lapalme et al, 2018;Vaillancourt et al, 2013;Yong et al, 2014). Also, the majority of past research employs a single informant for externalizing and internalizing problems (e.g., Boots et al, 2011;Burt & Roisman, 2010;Klostermann et al, 2016;van Lier et al, 2012).…”