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 ou tcome? Recent research shows that whereas goals are preferred for common ac tions, preconditions are preferred for actions that require substantial res ources particularly when those actions are obstructed. Two studies examined whether judgments of goals and preconditions reflect the controllability o f the events, and whether previous findings apply to events generated by pa rticipants. 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 explanatio ns than preconditions, whereas for the extreme scenarios, preconditions wer e judged equal or better explanations. The extreme events were seen as less controllable than the moderate events, and the controllability of the even ts predicted judgments of goals as explanations. The results suggest that p articipants see goals as better explanations only for events that the perso n can control, and they judge preconditions to be good explanations for eve nts where the person has little control. These findings suggest that equifi nality may apply only to those actions and outcomes where the preconditions are readily obtainable.