In the 1980s and 1990s, studies began to examine the continuity of aggression both in males and females. Taken together, these studies suggest that the continuity of aggression throughout the life course is slightly higher for males than for females. In the Dunedin Study in New Zealand, Moffitt et al. [2001] have followed over 1,000 children from age 3 to 26. Multiple informants reported on the child’s antisocial behavior across multiple time points. The pattern of longitudinal continuity correlations fit what Caspi and Roberts [1999] denoted as the “twin laws” of longitudinal correlations: the correlations decrease as the time between measurements increases, and the correlations for the same lag increase as the age of the participants increases. Across aggression measures and child ages, the correlations ranged from .74 to .32 for males and from .70 to .15 for females for a 1-year lag. For a 10-year lag, the correlations ranged from .36 to .12 for males and from .34 to 0 for females. In the Jyvaskyla Longitudinal Study of 369 Finnish children, Kokko et al. [in press], Pulkkinen and Pitkänen
