Mutability and the Availability of Counterfactuals

MUTABILITY AND THE AVAILABILITY OF COUNTERFACTUALS

Experienced facts evoke counterfactual alternatives against which people compare reality. Philosophical treatments of counterfactuals and possible worlds have explored the compelling intuition that some alternatives are closer to reality than others and that some changes of reality are smaller than others (see Lewis, 1973, for a particularly engaging treatment). As Hofstadter (1985) noted, the word almost provides a key to some of these intuitions. For example, the statement, “I almost caught the flight” is appropriate for an individual who reached the departure gate when the plane had just left, but not for a traveler who arrived half an hour late. The world in which the passenger arrives 5 minutes earlier than she did is closer to reality than a world in which she arrives half an hour earlier. The present analysis links these intuitions to mutability: A counterfactual possibility should appear “close” if it can be reached by altering some mutable features of reality.

Our notion of mutability is similar to the concept of slippability introduced by Hofstadter (1979, 1985). The shared ideas are that the mental representation of a state of affairs can always be modified in many ways, that some modifications are much more natural than others, and that some attributes are particularly resistant to change.

Another cognate of mutability is the distinction between the information presupposed and the information asserted in a verbal message (Clark & Haviland, 1977). The cleft sentence, “It was Tom who set fire to the hotel” designates an immutable aspect of the situation (the hotel was set on fire) and a mutable one (the identity of the arsonist). Note that either aspect of the sentence could be presupposed: “It was a hotel that Tom set on fire” has the same basic structure, with the two components interchanging their roles. The cleft sentence invites the listener to consider alternatives to the asserted content, even as it denies these alternatives. The presupposition is shared by all the alternatives.

As this example illustrates, presuppositions are highly flexible, and the relative mutability of attributes can be controlled almost at will. In the absence of deliberate intent or conversational guidance, however, differences in the mutability of attributes affect the spontaneous recruitment of norm elements.

The question for psychological research is which features of an event people spontaneously change in imagination, and how those alternatives affect their judgments.