This study investigated the normative use and developmental course of physical aggression (PA), defined as use of physical force such as hitting, biting, and kicking, from 8 to 26 months and predictors thereof. We used data from the Behavior Outlook Norwegian Developmental Study, comprising 1,159 children (559 girls and 600 boys). Both mothers and…

Children growing up in disharmonious families with anxious/depressed mothers are at risk for emotional and behavioral difficulties, however whether these associations reflect postnatal environment, prenatal exposure, or an overall liability is still unclear. This study used prospectively collected data from 24,259 participants of the Norwegian…