In the present study, we apply the preceding considerations to the study of trajectories of externalizing behavior problems across many years of development. Several studies have examined trajectories (defined here as 3 or more measurement occasions) of externalizing problems, including Odgers et al. (2008), which examined trajectories of antisocial conduct problems in individuals from New Zealand from ages 7–26 with 8 measurement occasions. A study using six longitudinal data sets examined trajectories of disruptive behaviors and delinquency, with the longest trajectory spanning ages 7–15 with 7 measurement occasions (Broidy et al., 2003). Another notable study examined trajectories of various externalizing problems in children from the Netherlands from ages 4–18 with 5 measurement occasions (Bongers, Koot, Ende, & Verhulst, 2004). Other studies have examined trajectories of other externalizing phenotypes, including aggression from ages 8–30 with 3 measurement occasions (Huesmann, Eron, Lefkowitz, & Walder, 1984) and from ages 8–42 with 4 measurement occasions (Kokko, Pulkkinen, Huesmann, Dubow, & Boxer, 2009). Studies have also examined trajectories of delinquency from ages 7–19 with 13 measurement occasions (Keijsers, Loeber, Branje, & Meeus, 2012) and from
