recent interest in criminal careers, which arose in the United States in the 1980s, has been criticized by the American criminologists Gottfredson and Hirschi as a mistaken investment (Gottfredson and Hirschi, 1986). The criticism stems from their perception of the age-crime curve as invariant across time, space crime types, and offenders (Gottfredson and Hirschi, 1990). If this is correct, developmental research becomes moot, since the criminal careers of all people, regardless of demographic or experiential contingencies, will progress along the same trajectories. Differences between individuals will be solely in terms of magnitude, a function of “self-control,” or “the extent to which they are vulnerable to the temptations of the moment” (Gottfredson and Hirschi, 1990, p. 87). Gottfredson and Hirschi argue that, given the invariance hypothesis, cross-sectional studies should be sufficient for identifying the causes and correlates of criminality and should be capable of doing so at a considerably lower cost. Believing as they do that all individuals follow a similar age-crime pattern (peaking in adolescence and declining thereafter), Gottfredson and Hirschi further question the usefulness of measurements related to single individuals as opposed to groups (Gottfredson and Hirschi, 1988). These concepts have been criticized as resulting largely from a misunderstanding of the methods and conceptualizations of the criminal career agenda (Blumstein, Cohen, and Farrington, 1988a; Blumstein, Cohen, and Farrington, 1988b).