“…As for age differences and perpetration of physical violence by youth, the findings are inconsistent. Several studies have indicated that the tendency toward violence increases with age (Pepler & Craig, 2005;Xie, Swift, Cairns, & Cairns, 2002), whereas others have suggested the opposite, that is, that perpetration of physical violence decreases with age (Steinberg & Morris, 2001). Perpetration of violence by youth has been found to be affected by the extent to which they behave in an impulsive manner (Moffitt, 1993;Vitulano, Fite, & Rather, 2010).…”