 One approach holds that psychological attributes confer moral status by virtue of the interests to which they give rise. This approach treats psychological attributes as the basis of interests that we have a prima facie obligation to advance, or at least not to thwart—an obligation whose strength varies with the strength and other features of those interests. The capacity to feel pain grounds an obligation to avoid its infliction; the capacity to anticipate and dread as well as feel pain may ground a stronger obligation. But if additional psychological capacities merely increased the strength of the interest, and the corresponding obligation to advance or not thwart it, an interest account would not provide a basis for a moral status threshold (McMahan 2002).