how the same construct is manifested over time, or heterotypic continuity. Following Rutter and Sroufe’s (2000) argument that developmental psychopathology research should strive to understand development over the lifespan, we were able to chart the development of externalizing behavior over years in one piece by using developmentally-appropriate, changing measures over time. An alternative approach for future studies might be to examine change over time in subdimensions of externalizing problems (e.g., physical aggression) in an attempt to focus on more homotypic patterns of change (e.g., Olson et al., 2013). Nevertheless, we feel there is utility in examining the construct of general externalizing behavior because 1) it is an efficient summary of many cases of psychopathology, 2) the subdimensions tend to co-occur, and 3) similar developmental processes appear to be involved with the different subdimensions (Olson, Bates, Sandy, & Lanthier, 2000).
