The Ordinary Concept of Personal Identity

What is required for an individual A at an earlier time to be the same person as an individual B at a later time? The philosophical literature on personal identity is rich, but here I present experimental evidence demonstrating that the ordinary concept of personal identity differs from that assumed by many of these philosophical discussions. Specifically, I challenge three common assumptions about the concept of personal identity: that moral judgment is irrelevant to personal identity, that personal identity is a necessary or sufficient condition for the application of moral concepts like just desert, and that the personal identity relationship is necessarily symmetric. In contrast, I find moral judgment does influence attributions of personal identity, for many personal identity is neither a necessary nor sufficient condition for desert, and in some cases an individual A is judged as identical to B, but B is judged as not identical to A.