Which of the following best explains why someone might act in a certain way based on external circumstances?

Attribution theory is a crucial framework in social psychology that explains how individuals interpret and understand the behavior of themselves and others based on situational factors. When someone acts in a particular way due to external circumstances, attribution theory helps in analyzing that behavior by examining the context in which it occurs.

For instance, if a person is late to a meeting, one might attribute this behavior to external circumstances such as traffic or a family emergency, rather than to inherent personality traits like irresponsibility. This reflects the core idea of attribution theory: it emphasizes the role of situational influences in behavior, helping to provide a more nuanced understanding of actions by considering the environment and context.

The other options address different concepts that, while related to understanding behavior, do not focus specifically on the explanation of actions based on external circumstances. For example, the bystander effect deals with people’s reluctance to intervene in emergencies when others are present; cognitive dissonance relates to the discomfort felt when holding conflicting beliefs; and actor/observer bias describes the tendency for people to attribute their own actions to situational factors while attributing others' actions to their character. These concepts do not specifically target the explanation of actions that result from external circumstances.