In Chapter 3, we considered explanations of behavior that draw solely on personality characteristics. Motives are relatively stable personality dispositions. Because the strength of the various motives differs interindividually, they can be invoked to explain differences in behavior. Indeed, motives can be seen as variables underlying predictable differences in individual behavior. In person-centered approaches, motive dispositions are also expected to explain the forces initiating and directing behavior. Seen from this perspective, situational factors serve only to arouse a particular motive. If, for example, someone with a strong achievement motive is invited to play a game of ludo (or Parcheesi), the achievement motive will take effect immediately, and determine that player's behavior from that moment on. Any differences between the players in this situation would have to be explained by motive-dependent motivational differences. As shown in Chapter 3, however, the explanatory value of models that rely solely on personality variables is limited. An alternative approach is one that focuses on situational variables, on the situational stimuli that trigger and direct behavior. In this chapter, we look at the major theoretical developments that have emerged from situation-centered explanations of behavior.

The early 20th century saw the emergence of a research tradition that took the equally radical approach of focusing on the situation as the sole determinant of behavior. Behaviorism turned its back on personality characteristics, and hence on motives, as explanatory variables. Indeed, behaviorists were less interested in individual differences than in the situational specificity of behavior. What initiates a behavioral sequence?