The identity of what? Pluralism, practical interests, and individuation

In this paper, we present a set of preregistered studies inspired by both Lockean pluralism about individuation and discussions of conjoined twinning in the contemporary personal identity debate. In combination, these studies provide evidence of folk pluralism about individuation of “individuals like us” and also ways in which individuation judgments are integral to practical interests. First, our studies show that individuation judgments depend on a sortal supplied. Study participants tend to see two people or persons but only one organism in case of dicephalic twins, and they do not find these two verdicts inconsistent. Second, study participants tend to be pluralist in a sense that they find it acceptable to consider dicephalic twins to be—at the same time—two persons sharing one body and one two‐headed person. Third, while both perspectives are available, when reasons for counting are made salient, study participants tend to resolve pluralism in line with practical interests relevant in the context.