predictors of externalizing problems (e.g., physical harm, positive parenting) could be subsumed under other parenting variables (e.g., spanking, harsh discipline). In other cases, some risk factors may be more salient to the individual (e.g., individual stress) than others (e.g., family stress). Another possibility is that some risk factors may have different effects at different developmental periods. For example, stress may be experienced particularly acutely in later adolescence because of the lagging development of the PFC relative to the earlier developing limbic areas (Petersen et al., 2012).
