One: but not the same

Ordinary judgments about personal identity are complicated by the fact that phrases like “same person” and “different person” have multiple uses in ordinary English. This complication calls into question the significance of recent experimental work on this topic. For example, Tobia (Anal 75: 396–405, 2015) found that judgments of personal identity were significantly affected by whether the moral change described in a vignette was for the better or for the worse, while Strohminger and Nichols (Cogn 131: 159–171, 2014) found that loss of moral conscience had more of an effect on identity judgments than loss of biographical memory. In each case, however, there are grounds for questioning whether the judgments elicited in these experiments engaged a concept of numerical personal identity at all (cf. Berniūnas and Dranseika in Philos Psychol 29: 96–122, 2016; Dranseika in AJOB Neurosci 8: 184–186, 2017; Starmans and Bloom in Trends Cogn Sci 22: 566–568, 2018). In two pre-registered studies we validate this criticism while also showing a way to address it: instead of attempting to engage the concept of numerical identity through specialized language or the terms of an imaginary philosophical debate, we should consider instead how the identity of a person is described through the connected use of proper names, definite descriptions, and the personal pronouns “I”, “you”, “he”, and “she”. When the experiments above are revisited in this way, there is no evidence that the differences in question had an effect on ordinary identity judgments.