Constraints on equifinality: goals are good explanations only for controllable outcomes

What makes a goal or a precondition a better explanation of an action or outcome? Recent research shows that whereas goals are preferred for common actions, preconditions are preferred for actions that require substantial resources, particularly when those actions are obstructed. Two studies examined whether judgments of goals and preconditions reflect the controllability of the events, and whether previous findings apply to events generated by participants. Participants judged goals and preconditions as explanations for desirable extreme and moderate events and assessed the controllability and probability of the events. For common events, goals were better explanations than preconditions, whereas for the extreme scenarios, preconditions were judged equal or better explanations. The extreme events were seen as less controllable than the moderate events, and the controllability of the events predicted judgments of goals as explanations. The results suggest that participants see goals as better explanations only for events that the person can control, and they judge preconditions to be good explanations for events where the person has little control. These findings suggest that equifinality may apply only to those actions and outcomes where the preconditions are readily obtainable.