Third, as Lewin observed, actors are a part of their own life space; other people respond to physical and social characteristics of the actor in ways that in turn influence the actor (Gilbert & Jones, 1986). Finally, both personal factors and situational factors create “cumulative consequences” in a way that magnifies the effects of either and produces stability over time (Caspi, Bem, & Elder, 1989; Caspi, Elder, & Bem, 1987, 1988).