How stable is antisocial behaviour? Even in the 1970s, during the heyday of ‘situationism’ in psychology, behavioural scientists acknowledged that individual differences in aggressive behaviour are stable (Olweus, 1979). Longitudinal studies completed both before and after Olweus' review showed that antisocial behaviour was predictable from one point in time to another (e.g., Huesmann et al., 1982; Farrington, 1986; Macfarlane, Allen, and Honzik, 1954; Stattin and Magnusson, 1991b; Pulkinnen and Pitkanen, 1993; Patterson, Reid, and Dishion, 1992; Stanger, Achenbach, and Verhulst, 1997). However, most of the studies of the stability of antisocial behaviour have examined only males because historically few longitudinal studies of antisocial behaviour have sampled girls; in fact, the two most oftcited authoritative reviews on the topic of the stability of antisocial behaviour reviewed studies of males only (Loeber, 1982; Olweus, 1979). Some authors state that antisocial behaviour is less stable and predictable among females than among males (e.g., Cairns and Cairns, 1984; Moss and Susman, 1980), while other authors state that there is no reliable sex difference in the stability of antisocial behaviour (Cairns and Cairns, 1994; Tremblay et al., 1992). In our reading of the literature, we were impressed at how often each view was stated with confidence. Both cannot be correct.

The goal of this chapter is to test whether antisocial behaviour is equally stable from childhood to adolescence to adulthood in both males and females.