Everett, Skorburg, & Savulescu (2020) Philosophical Psychology The Moral Self and Moral Duties Jim A.C. Everett1,2,4, Joshua August Skorburg3, & Julian Savulescu4 1 School of Psychology, University of Kent 2 Department of Psychology, Leiden University 3 Department of Philosophy, Duke University 4 Uehiro Centre for Practical Ethics, University of Oxford Manuscript Published in Philosophical Psychology Abstract Recent research has begun treating the perennial philosophical question, "what makes a person the same over time?" as an empirical question. A long tradition in philosophy holds that psychological continuity and connectedness of memories are at the heart of personal identity. More recent experimental work, following Strohminger & Nichols (2014), has suggested that persistence of moral character, more than memories, is perceived as essential for personal identity. While there is a growing body of evidence supporting these findings, a critique by Starmans & Bloom (2018) suggests that this research program conflates personal identity with mere similarity. To address this criticism, we explore how loss of someone's morality or memories influence perceptions of identity change, and perceptions of moral duties towards the target of the change. We present participants with a classic 'body switch' thought experiment and after assessing perceptions of identity persistence, we present a moral dilemma, asking participants to imagine that one of the patients must die (Study 1) or be left alone in a care home for the rest of their life (Study 2). Our results highlight the importance of the continuity of moral character, suggesting lay intuitions are tracking (something like) personal identity, not just mere similarity. Keywords personal identity; morality; moral self; experimental philosophy Author Note This work was supported by a sub-award given to JACE and JAS through the 2016 Summer Seminars in Neuroscience and Philosophy (SSNAP) programme, funded by the John Templeton Foundation. Further support was given through the Wellcome Centre for Ethics and Humanities and Wellcome Trust grants (WT203132 / WT104848) awarded to JS, along with the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant (707404) for JACE. Correspondence can be directed at Jim A.C. Everett at Keynes College, Canterbury, Kent or j.a.c.everett@kent.ac.uk Everett, Skorburg, & Savulescu (2020) Philosophical Psychology Post-Print 2 The Moral Self and Moral Duties The idea of body-switches – waking up with your mind in someone else's body – has been an enduring feature of popular culture, from children's books like Mark Twain's The Prince and The Pauper to cult-classic movies like Freaky Friday. These stories raise deep questions about what makes a person the same person over time. There is, of course, a long tradition of philosophical debate about these questions. A prominent view, associated with John Locke, posits that psychological continuity, and specifically memories, are at the heart of personal identity: Person X at Time 1 can be identified as Person Y at Time 2, if X and Y share an autobiographical memory (Locke, 1694/1975). Indeed, some empirical evidence using body-switch thought experiments indicates that this philosophical perspective tracks folk intuitions, with participants judging that after transplanting a patient's (Jim) brain into the body of another patient, the patient was ''still Jim'' when the memories were preserved, but not when memories were erased (Nichols & Bruno, 2010). More recent work has suggested that while memories are surely important in this regard, so too are other features of the mind. More specifically, moral traits have been proposed as especially identity-conferring (Everett, Skorburg, Livingston, Chituc, & Crockett, Under Review; Heiphetz, Strohminger, Gelman, & Young, 2018; Heiphetz, Strohminger, & Young, 2017; Molouki & Bartels, 2017; Stanley, Bedrov, Cabeza, & De Brigard, Under Review; Strohminger, Knobe, & Newman, 2017; Strohminger & Nichols, 2014, 2015). For example, Strohminger & Nichols (2014) presented participants with a wide variety of traits and asked participants to imagine how much a change to a specific trait would influence whether someone is the same person (e.g. "Jim can no longer remember anything that happened before the accident. Aside from this, he thinks and acts the same way as before the accident. Is Jim still the same person as before the accident?") Across five experiments, participants reported that when a person changes in terms of traits like honesty, empathy, or virtuousness, they were rated as more of a different person than when they changed in terms of memories, preferences, or desires. Thus, "moral traits are considered more important to personal identity than any other part of the mind" (Strohminger & Nichols 2014, p. 168). This "moral self effect" has been demonstrated with 8 to 10year-olds (Heiphetz et al., 2018), and holds whether participants are thinking of the self, a friend, or a stranger (Everett et al., Under Review; Heiphetz et al., 2017). This moral self effect is thought to occur in large part because morality is one of the fundamental dimensions on which we perceive others, and changes to morality will likely have much greater influence on the broader community than changes to memories (Everett et al., Under Review; Heiphetz et al., 2017). In short, losing one's memories is bad individually and bad for close friends/family, but losing one's moral conscience will likely have a much greater negative impact on a much broader range of people. However, a recent critique by Starmans & Bloom (2018) suggests that this research on the moral self effect rests on a mistake. They argue that the studies fail to distinguish similarity and qualitative (or biographical) identity on the one hand, from personal identity and quantitative (or numerical) identity on the other (Parfit, 1984). Twins, for example, can be qualitatively identical, but are still quantitatively distinct people: you might not be able to tell them apart, but they still need two passports to travel abroad. This distinction between numerical and qualitative identity has previously been used to criticise the early studies on the importance of memories to identity persistence (e.g. Blok, Newman, & Rips, 2005; Nichols & Bruno, 2010). Berniūnas and Dranseika (2016) argue that these designs do not adequately distinguish between qualitative and numerical identity judgments. For example, when Nichols and Bruno (2010) ask participants "What is Everett, Skorburg, & Savulescu (2020) Philosophical Psychology Post-Print 3 required for some person in the future to be the same person as you?", it is possible that participants are interpreting this question in a qualitative, not numerical sense. To test this, they draw on a convenient pair of Lithuanian phrases that disambiguate the two: tas pats and toks pats. When contrasted with toks pats, tas pats means "the same" in the sense of numerical identity while toks pats means "the same" in the sense of qualitative identity. When explicitly disambiguating these two senses to their Lithuanian participants, they found that participants were significantly more likely to agree that someone was the "same person" after losing their memories, suggesting that "retention of memory may not be so critical to the preservation of individual numerical identity" (Berniunas & Dranseika, 2016, p.115). Focusing on the moral self effect research, Starmans and Bloom (2018) draw on the same distinction between numerical identity and similarity to make a more forceful critique, suggesting that previous work has intended to focus on the former, but really has just looked at the latter. If Jim lost his moral conscience after an accident, then it might make sense to say that he seems like a different person. He's qualitatively, or biographically, dissimilar to who he was before the accident. But it wouldn't make sense, according to Starmans & Bloom, to suggest that post-accident-Jim is quantitively distinct from pre-accident-Jim, such that pre-accident-Jim's debts are now forgiven, or that post-accident-Jim must now get a new passport. Jim is still the same person, he's just dissimilar from before. In other words, when participants in the "moral self effect" studies report things like "I completely disagree Jim is the same person as before the accident," they are referring to similarity (qualitative identity) and not strictly personal or quantitative identity. Starmans & Bloom suggest that this conceptual confusion can be avoided by using wellestablished paradigms in cognitive and developmental psychology which study the numerical identity of objects. Setting that suggestion to the side, we think there are theoretical ways to respond to Starmans and Bloom's challenge, namely by calling into question whether it is desirable – or even possible – to strictly divide similarity from numerical identity. We will return to this in the general discussion. For now, we turn our attention to an empirical response to their challenge. One way to address the adequacy of Starmans and Bloom's critique on empirical grounds is to look at the practical consequences of judgements of identity change. In our recent work, we found that, compared to memories, social changes generally and moral changes specifically, not only affected perceptions of identity persistence (as in previous studies), but crucially, such changes also led participants to subsequently infer a range of practical consequences, including changes in behavior, evaluations by third parties, and reductions in relationship quality (Everett et al., Under Review). There are many ways in which judgements about identity persistence have practical consequences, as Tobia (2015; 2016) and many others have discussed. After all, questions about personal identity are deeply linked with ethical considerations (see, e.g., Shoemaker, 2016). Most obviously, personal responsibility presupposes personal identity: I can only be held morally responsible for my actions, not someone else's. Similarly, consider moral duties to one's parents. These can be described as special obligations, owed to one's parents simply because of the relationship one has to them and the persons they are (Jeske, 2014). These special obligations can be distinguished from natural duties, or those "moral requirements which apply to all men [and persons] irrespective of status or of acts performed...owed by all persons to all others" (Simmons, 1979, p. 13). I have obligations to my mother that I don't have to a stranger, and these special obligations towards my mother don't change after she colors her hair, changes her job, or undergoes a sex reassignment procedure. My obligations and duties to her are the same because she herself is the same person. Everett, Skorburg, & Savulescu (2020) Philosophical Psychology Post-Print 4 Focusing on moral duties in this way may not settle the qualitative vs quantitative debate about personal identity once and for all, but it can circumvent Starman & Bloom's criticism. If participants are thinking, at least in part, about forensic identity in some Lockean sense (see also discussion) and not just similarity, we should expect that judgments about moral duties should partially track judgments of change. If, for example, I judge that my mother is still the same person after losing her memories, I should also judge that I have the same special obligations towards her. If I judge that she is a different person, in contrast, it seems plausible that my perceptions of special obligations towards her will also change accordingly. In contrast, if Starmans and Bloom are correct that participants are just thinking about similarity and not identity, participants should rate someone who loses their morals as different, but should not perceive any changes to their own moral duties towards that person. The Present Studies Here, we explore how changes to moral traits and memories influence both perceptions of identity change, and also the practical consequences that follow from such judgements. More specifically, we examine perceptions of moral duties towards the target of the change. We present participants with a classic 'body switch' thought experiment in which a loved one undergoes a brain transplant with a stranger, and as a consequence, either experiences no psychological change, loses all their memories, or loses their moral conscience. After assessing perceptions of identity persistence, we present a moral dilemma, asking participants to imagine that one of the patients must die (Study 1) or be left alone in a care home for the rest of their life (Study 2). Participants must decide who to save or care for: the patient with their partner's brain and the stranger's body, or the patient with the stranger's brain and the patient's body. Study 1 Method Open Science All measures, manipulations, and exclusions, and all data, analysis code, supplementary results, and experiment materials are available for download at: https://osf.io/wehkn/ Design 296 American participants completed the survey online using Amazon Mechanical Turk and received $0.80 for their time. Participants were excluded from analysis if they took the survey more than once (N = 6), leaving a final sample of 290 participants (108 female, Mage = 33, SD = 8.84). This study had three conditions: one where the patient had no discernable change after the operation ("control"); one where the patient lost all of their memories ("memories"); and one where the patient lost their moral conscience ("morality"). At the start of the study, participants were told that for this task we needed them to think of someone that is very close to them. Participants were told that it did not matter who the person they're thinking of is, or what their specific relationship to the participant is, as long as they are close to the participant. Participants were given a list of fourteen options of the person they were thinking of, which we hoped would cover most, if not all, the people participants could think of (mother; father; son; daughter; brother; sister; husband; wife; partner; friend; grandmother; grandfather; cousin; aunt; uncle). After selecting and confirming their decision, participants were told that they would be taking part in a short imagination exercise. The story revolved around a "mad scientist" who had kidnapped a number of people, including the person that the participant indicated they were thinking about. In the story (and for all the subsequent measures) we used piped text to feed back the person into the story (e.g. "There is a mad scientist who has kidnapped a number of people, Everett, Skorburg, & Savulescu (2020) Philosophical Psychology Post-Print 5 including your [friend/husband/aunt, etc.]" This was done to enhance the plausibility of what is, of course, quite an unusual story. For the remainder of the paper we shall refer to the person the participant was thinking of simply as their 'partner'. In all three conditions the story began the same way: "There is a mad scientist who has kidnapped a number of people, including your [partner]. The scientist plans to test a new and unapproved procedure that would allow full brain transplants. The scientist knows that if this works it would revolutionise medicine, but because the procedure is risky they have not been able to find willing participants. Because the scientist has not found anyone who is willing, they have kidnapped a group of people, including your [partner] and is going to perform the procedure on them. The scientist performs the operation, and places the brain of your [partner] into a stranger's body, and places the stranger's brain into your [partner's] body. The operation appears successful. All the right neural connections have been made, and after testing all physiological responses the scientist determines that the patients are alive and functioning." The next part of the story differed by condition. In the control condition, participants were told that there was no psychological change: "The patient with your [partner's] brain and the stranger's body thinks and acts just like your [partner] did before the operation". In the memories condition, participants were told that "both patients have completely lost all of their memories: neither patient can remember anything that has happened to them before the operation", though apart from this they were the same. And finally, in the moral trait condition, participants were told that "both patients have completely lost all of their moral consciences: neither patient cares about the people they used to care about, and shows no emotional reaction when the scientist threatens to torture and hurt those people. Both patients appear to no longer be capable of judging right from wrong, or being moved by the suffering of others", although apart from this they were the same. After completing questions concerning the psychological persistence of their partner, participants were then introduced to the second part of the story. This part was also identical across the conditions. Participants were told that: "After the operation on the stranger and your [partner], the scientist's actions were discovered. Luckily, the other people they kidnapped were not operated on. While being captured, the scientist was killed and the two patients (the stranger and your [partner]) were taken into hospital to be monitored. Unfortunately, while the patients seemed fine at first, doctors discover serious abnormalities. Looking through the things of the scientist, they discover that the scientist had anticipated this and had developed an injection that would cure this. There is, however, only enough for one person, and with the scientist being dead, the doctors cannot create more. One of the patients must die." After reading this, participants were asked some questions about which patient they should save. Finally, on a new page, participants were told to "assume that the patient with your [partner's] brain and the stranger's body is your 'real' [partner] and this is the patient you decided to save", and were asked questions about whether their partner is now the same person as before, whether they will behave differently to how they do now, and whether their relationships will change from how they are now. Everett, Skorburg, & Savulescu (2020) Philosophical Psychology Post-Print 6 Measures Psychological Identity Persistence First, participants completed a categorical identification question in which they were asked to identify "which of the two patients is your [partner]?" Participants had three options for this question: the patient with the partner's brain and the stranger's body; the patient with the stranger's brain and the partner's body; or neither. Second, we measured psychological identity persistence with three items measuring whether participants thought that the patient who now had the brain of their partner was in fact their partner. First, participants were asked "To what extent is this patient with your [partner's] brain and the stranger's body your [partner]?1" (1 = definitely not my partner; 7 = definitely is my partner). Second, participants were asked "To what extent is this patient with your [partner's] brain and the stranger's body identical to your [partner]?" (1 = completely different; 7 = completely identical). Third, participants were asked "To what extent is this patient with your [partner's] brain and the stranger's body the same person they were before?" (1 = completely different; 7 = completely identical). Scores on these three questions showed the same pattern of results and were positively correlated (all rs > .45, ps < .001) so we combined these scores into a reliable composite measure of psychological identity persistence (α = .75). Results with each sub-item individually showed the same pattern, and are reported in full in the supplementary results. Moral Duties To measure participants' sense of moral responsibility towards the patients, participants were first asked two categorical questions: first, which of the patients (if any) they should choose to let live; and second, which of the patients (if any) they had a duty to protect. For both questions, participants had three options: the patient with the partner's brain and the stranger's body; the patient with the stranger's brain and the patient's body; or neither. Third, participants were asked to indicate how morally wrong it would be to sacrifice the patient with the partner's brain (1 = not at all morally wrong; 7 = extremely morally wrong) Consequences of Identity Change Finally, we had participants assume that they saved the patient with their partner's brain and the stranger's body and asked two questions assessing how they expected their partner's social life and interactions to change as a result of the operation. First, we asked participants to what extent their partner's relationships will change from how they are now, and second, to what extent their partner will now behave differently (1 = not at all, 7 = very much). Results Identity Persistence First, we looked at identity persistence. Across all conditions, participants adopted a psychological account of identity persistence, with most participants judging that the 'real' partner was the patient with their partner's brain and a stranger's body, and few judging that the 'real' partner was the one with the stranger's brain but the partner's body (< 9%; see Table 1). Compared to the control condition (18%), participants were more likely to judge that neither patient was their real partner (40%) when they had completely lost their moral conscience, x2(1) 1 For completeness, we also asked participants to indicate how much the patient with the partner's body and the stranger's brain was the real partner, but do not report this in the main manuscript given that participants overwhelmingly adopted a psychological view of identity persistence. Similarly, while we also asked participants to indicate how wrong it would be to sacrifice the patient with the partner's body and stranger's brain, in the interests of space and clarity we focus on judgments of sacrificing the brain-patient. Results for these additional questions are reported in the supplementary results. Everett, Skorburg, & Savulescu (2020) Philosophical Psychology Post-Print 7 = 7.14, p = .008. And in the moral trait condition but not the control or memories there was no significant difference between how many participants said that the partner-brain-patient (i.e. the patient with the partner's brain but the stranger's body) was the real partner (51%) and how many said that neither was the real partner, x2(1) = 1.45, p = .23. "Which of the two patients is your partner?" Patient with the partner's brain, and stranger's body Patient with the stranger's brain, and partner's body Neither Control 76% 6% 18% Loss of Memories 63% 5% 32% Loss of Morals 51% 9% 40% Table 1. Percentage of participants in Study 1 judging that each (or neither) patient was the 'real' partner, as a function of whether they experienced no psychological change (control condition), lost their memories, or lost their morals. Similar results were found when looking at ratings of how much the patient with the partner's brain and the stranger's body was in fact the real partner (see Fig. 1A). We observed a significant effect of change condition, F(2,287) = 14.90, p < .001, ηp2 = .09, whereby compared to when they changed morally, participants were significantly more certain that the partner-brainpatient was their real partner when they had not changed at all (t = 5.31, p < .001) or lost their memories (t = 3.78, p = .008). In contrast, there was no difference in ratings of identity persistence between the control and memories condition (t = 1.48, p = .30). Together, these results highlight that people perceived that continuity of the mind is more important than continuity of the body, but within this, continuity of one's moral conscience is perceived to be more important than continuity of one's memories. Everett, Skorburg, & Savulescu (2020) Philosophical Psychology Post-Print 8 Figure 1. Perceived identity persistence and wrongness of sacrificing as a function of condition (no psychological change; loss of memories; loss of moral conscience). Higher scores indicate more perceived identity persistence (1A) and more perceived moral wrongness (1B). Error bars represent 95% confidence intervals. Moral Duties Second, we looked at perceived moral duties towards the patients. When asked who to save, across all conditions, the majority of participants said that if forced to decide, they would save the patient with their partner's brain and a stranger's body. As for the identification question, however, significantly more participants indicated that they would save neither patient when the patients had lost their moral conscience compared to when they lost their memories, x2(1) = 10.70, p = .001, or experienced no psychological change, x2(1) = 7.76, p = .005, with no difference between the control and memories condition x2(1) = 0.33, p = .56 (see Table 3). "The patient you choose will live; the other one will die. Who do you choose to live?" Patient with the partner's brain, and stranger's body Patient with the stranger's brain, and partner's body Neither Control 81% 12% 7% Loss of Memories 86% 8% 5% Loss of Morals 67% 10% 23% Table 2. Percentage of participants in Study 1 choosing to save each (or neither) patient, as a function of whether they experienced no psychological change (control condition), lost their memories, or lost their morals. Everett, Skorburg, & Savulescu (2020) Philosophical Psychology Post-Print 9 When asked directly about which patient they had a moral duty to protect (see Fig. 2), for all conditions, most participants said that they had a duty to protect the patient with their partner's brain, though again significantly more participants said they had no moral duty to protect neither patient in the moral condition compared to the control condition x2(1) = 4.41, p = .04. There was no difference between the morality and memories conditions, x2(1) = 0.83, p = .36, and no difference between the control and memories conditions, x2(1) = 1.45, p = .23 Figure 2. Number of participants indicating the patient they felt they had a duty to protect, broken down by whether the patient experienced no psychological change, lost their memories, or lost their moral conscience. And finally looking at the rated wrongness of sacrificing the brain-patient (see Fig 1B), we found a significant effect of change condition, F(2,287) = 5.22, p = .006, ηp2 = .04, such that sacrificing the patient was seen as significantly more wrong when the patient experienced no psychological change than when they lost their moral conscience (t = 3.19, p = .005), and marginally-but non-significantly more wrong to sacrifice the patient when they had lost their memories than when they had lost their moral conscience (t = 2.23, p = .068). There was no difference between the control and memories conditions, (t = 0.94, p = .62). Consequences of Change Finally, all participants were asked to focus just on the patient with the partner's brain, and we looked at the perceived consequences of the change: relative to when they experienced no psychological, only physiological, changes, how much did participants expect that someone who lost their moral conscience or memories would behave differently, and how much would this negatively affect their relationships? In line with previous work (Everett et al., Under Review), we found a significant effect of condition on expected behavior change, F(2,287) = 16.62, p < .001, ηp2 = .01, with participants expecting greater behavior change after they lost their moral conscience than when they lost their memories or experienced no psychological change, with all pairwise comparisons being significantly different (see Fig 3A). Similarly, we found a significant effect of condition on expected relationship change, F(2,287) = 22.67, p < .001, ηp2 = .014, again with Everett, Skorburg, & Savulescu (2020) Philosophical Psychology Post-Print 10 participants expecting that their partner's relationship would change the most after they lost their morals than when they lost their memories or experienced no change (see Fig 3B). There was no significant difference in expectations of relationship change between the control and memories condition. Figure 3. Consequences the body-switch as a function of condition (no psychological change; loss of memories; loss of moral conscience). Higher scores indicate a higher degree of change, and thus identity disruption. Error bars represent 95% confidence intervals. Discussion In Study 1 we found that, consistent with previous work, a loss of moral conscience led participants to judge that a person's identity would be more disrupted than if they lost all their memories. We also showed that these judgements might have practical consequences: a person who lost their moral conscience, more so than their memories, was expected to behave more differently and participants expected to have a worse relationship with them. Moreover, participants' perceived fewer moral duties towards a loved one who lost their moral conscience than one who lost their memories. These results are consistent with – though not, of course, direct proof of – the idea that participants are judging the person's identity to be more disrupted after changes to morality, and not only judging perceptions of similarity. Even if participants are considering similarity, it seems they are still judging it more disruptive for someone to lose their moral conscience than their memories, plausibly because this is a worse fate that affects more people (given the social nature of morality, a loss of morals is likely to affect the lives of others' more negatively than a loss of memories would affect the lives of others). Study 2 In Study 2 we sought to replicate the results of Study 1 in a slightly different context, looking not at which patient participants thought should be sacrificed, but which patient participants thought they had a moral responsibility to care for. Everett, Skorburg, & Savulescu (2020) Philosophical Psychology Post-Print 11 Method Open Science All measures, manipulations, and exclusions, and all data, analysis code, and experiment materials are available for download at: https://osf.io/gzywt/ Design 292 American participants completed the survey online using Amazon Mechanical Turk and received $0.80 for their time. Participants were excluded from analysis if they took the survey more than once (N = 4), leaving a final sample of 288 participants (135 female, Mage = 35, SD = 10.80). This study was identical to Study 1 (same "control", "memories", and "morality" conditions), except that instead of being asked which of the two patients to save with an injection, participants were asked which of the patients they should care for. More specifically, participants were shown the following text: "The doctors explain that as you are the closest person to your [partner], if you wish you can take one of the patients home and care for them until their death. This will require you taking time off work and becoming a full-time carer for them as they become progressively more and more sick. The doctors explain that they are only offering this option to you as a legal requirement, and there is no obligation to take either patient home. They are unable to find a contact for the stranger, and so the patient(s) you do not choose will remain in hospital until their death." The dependent measures from Study 1 were adapted accordingly for this scenario (e.g. "How morally required is it to care for the patient with your [partner's] brain and the stranger's body?) Results Identity Persistence First, we looked at identity persistence. Across all conditions, participants again adopted a psychological account of identity persistence, with most participants judging that the 'real' partner was the patient with their partner's brain and a stranger's body, and few judging that the 'real' partner was the one with the stranger's brain but the partner's body (< 10%: see Table 3). There was no difference in choices between the three conditions. "Which of the two patients is your partner?" Patient with the partner's brain, and stranger's body Patient with the stranger's brain, and partner's body Neither Control 65% 10% 26% Loss of Memories 60% 9% 31% Loss of Morals 59% 8% 33% Table 3. Percentage of participants in Study 2 judging that each (or neither) patient was the 'real' partner, as a function of whether they experienced no psychological change (control condition), lost their memories, or lost their morals. Surprisingly – given results from Study 1 and responses on the other dependent measures there was no difference in ratings of psychological identity persistence between the three conditions, F(2,285) = 1.49, p = .23, ηp2 = .01. Participants thought their partner's identity was Everett, Skorburg, & Savulescu (2020) Philosophical Psychology Post-Print 12 equally disrupted when they lost their moral conscience as when they lost their memories or experienced no psychological change at all. Moral Duties Second, we looked at participants' perceived moral duties towards the patients. When asked who to care for, across all conditions the majority of participants said that if forced to decide, they would care for the patient with their partner's brain and a stranger's body. As for the identification question, significantly more participants indicated that they would care for neither patient when the patients had lost their moral conscience compared to when they experienced no psychological change x2(1) = 6.15, p = .013. There was, however, no difference in the incidence of people choosing to save neither depending on whether they lost their memories or their morals, x2(1) = 0.62, p = .43, and only a marginal difference between the memories and control conditions x2(1) = 2.95, p = .09 (see Table 4). "Which patient – if any – do you take home to care for?" Patient with the partner's brain, and stranger's body Patient with the stranger's brain, and partner's body Neither Control 76% 9% 16% Loss of Memories 61% 12% 28% Loss of Morals 63% 5% 32% Table 4. Percentage of participants in Study 2 choosing to care for each (or neither) patient, as a function of whether they experienced no psychological change (control condition), lost their memories, or lost their morals. When asked directly about which patient they had a moral duty to protect, for all conditions most participants said that they had a duty to protect the patient with their partner's brain, though there were no significant differences between the three change type conditions. There was no difference between the morality and control condition in likelihood of saying one had a moral duty towards neither patient, x2(1) = 2.08, p = .15, nor between the morality and memories condition, x2(1) = 0.07, p = .79, nor the memories and control condition, x2(1) = 1.39, p = .24. Turning to the scale-ratings, there was a significant effect of change type on participants' perceived duty to care for the brain-patient, F(2,285) = 5.22, p = .006, ηp2 = .04, with participants indicating that they had less of a moral duty to care for the brain-patient when they had changed in terms of memories (t = 2.65, p = .02) or morality (t = 2.92, p = .01) than when they had experienced no psychological change (but with no difference between the memories and morals conditions: t = 0.23, p = .97). Similarly, there was a significant effect of change type on reported wrongness of leaving and not helping the brain-patient, F(2,284) = 9.53, p < .001, ηp2 = .06, with participants indicating that it would be less wrong to leave the brain-patient when they had changed in terms of memories (p < .001) or morality (p = .02) than when they had experienced no psychological change, but with no difference between the memories and morality conditions (p = .26). Everett, Skorburg, & Savulescu (2020) Philosophical Psychology Post-Print 13 Consequences of Change Finally, asking participants to focus just on the patient with the partner's brain, we looked at the perceived consequences of the change: Relative to when they experienced no psychological and only physiological changes, how much did participants expect that someone who lost their moral conscience or memories would behave differently, and how much would this negatively affect their relationships? In line with previous work (Everett et al., Under Review), we found a significant effect of condition on expected behavior change, F(2,285) = 15.66, p < .001, ηp2 = .01, with participants expecting greater behavior change when the patient lost their moral conscience than when they lost their memories or experienced no psychological change, but with no difference between the control and memories conditions. Similarly, we found a significant effect of condition on expected relationship change, F(2,285) = 5.71, p = .004, ηp2 = .04, with participants expecting that their partner's relationship would change the most after they lost their moral conscience than when they experienced no change, but with no difference between the control and memories condition, nor between the memories and morality conditions. General Discussion A growing body of work has suggested that, contra the traditional philosophical view that memories are critical for identity persistence, it is instead moral values that are perceived to central, and essential for personal identity (e.g. Everett et al., Under Review; Heiphetz et al., 2017; Strohminger & Nichols, 2014). In this paper we sought to extend this line of work, looking not just at how different changes influence abstract judgements of identity persistence, but how these judgements have practical consequences, and also, the extent to which focusing on such consequences addresses recent criticisms of the research on the moral self effect. An initial first step in this paper was to look at direct ratings of identity persistence, testing whether personal identity is more disrupted by loss of morals than by a loss of memories (or no psychological change at all). In this endeavor we surprisingly had mixed results. In Study 1, we replicated previous findings (e.g. Everett et al., Under Review; Heiphetz et al., 2017; Strohminger & Nichols, 2014), showing that participants did think that a person's identity would be more disrupted if they lost their moral conscience than if they lost all their memories or experienced no psychological change. This was seen in scale ratings of identity persistence (as in previous work), but also in categorical decisions of which patient was the 'real' partner after a body switch, where significantly more participants thought neither patient was the 'real' partner when they lost their memories. It was surprising to us, then, that we did not replicate these results in our second pre-registered study. It is not clear to us why this would be so, given that the dependent measures and written instructions were almost identical between the two studies, we used the same analyses in both studies, and this general pattern of results has been widely replicated in previous research across a variety of contexts. Regardless, another central aim in this paper was to look at the practical consequences of identity change judgments and the extent to which these judgments influence a) participants perceptions of moral duties towards their partner, b) perceived relationship quality, and c) expectations of future behavior change. Again, results from Study 1 supported predictions: participants perceived their moral duties towards their partner to be reduced when the partner had lost their moral conscience; expected their partner to behave more differently when they lost their morals than when they lost memories or experienced no psychological change; and expected that their relationship with the partner would change more if the partner lost their morals than if they lost their memories. Everett, Skorburg, & Savulescu (2020) Philosophical Psychology Post-Print 14 Results from Study 2 did not show the same pattern – likely in large part because we failed to replicate the basic finding that people view loss of morals as more disruptive for identity than a loss of memories. Participants were quite consistent, however, in thinking that their moral duties towards the patient were reduced when the person has changed, but there were few differences between perceived moral duties towards a patient depending on whether they lost their memories or morals. Despite the mixed nature of this particular result, our findings still advance the recent debate about qualitative vs. quantitative identity, which we discuss in more detail below. One final noteworthy feature of our work is that we did partially replicate previous results using a different paradigm than is usually employed. Typically, this work has used a within-subjects paradigm in which participants are presented with a series of different types of changes and asked to rate for each how much a person would be a different person after changing in that one specific way, assuming that everything else about them remained the same (though for an exception see Study 1 of Strohminger & Nichols, 2017). One might argue that presenting these changes in this manner is not strong enough to cause real identity change. That is, losing a single memory might not disrupt identity, but losing a whole series of connected memories – as in complete amnesia, like in our experiments might indeed make someone a different person. That we observe the moral self effect (at least in Study 1) when using the alternative within-subjects paradigm provides further evidence that the effect is robust and not simply an artifact of the particular experimental paradigm typically used. Similarity or Identity? Starmans and Bloom (2018) have claimed that previous empirical work on the moral self effect is about similarity and not personal identity. We wanted to see if we could address this challenge empirically by leveraging the idea of special obligations, or the duties we have to someone simply because of who they are. Ethically, we might think that I have obligations to my mother that I don't have to a stranger, and these special obligations towards my mother do not change even if she were to suffer a severe, debilitating stroke that changed her personality. My obligations and duties to her are the same because she herself is the same person, however dissimilar she is now to how she was in her prime. In this way, if participants are thinking (at least in part) about identity, and not just similarity, we should expect that judgments about moral duties should partially track judgments of change: when participants judge that someone is more of a different person when they lose their morals than their memories, they should also be more likely to say that their moral duties towards that person are more reduced when they lose their morals than their memories. If, in contrast, Starmans and Bloom are correct that in these kinds of experiments participants are just thinking about similarity and not identity, participants should rate someone who loses their morals as more different, but should not perceive any changes to their own moral duties towards that person. In Study 1, we found results that were consistent with the idea that participants are thinking about both identity and similarity2. When asked who to save (patient with the stranger's brain and partner's body, or the partner's body and the stranger's brain), participants who were told the patients had completely lost their morals were more likely to say they would save neither patient, compared to participants who were told the patients had lost their memories or experienced no psychological change. Similarly, sacrificing the patient with their partner's brain and the stranger's body was seen as significantly more wrong when the patient experienced no 2 In Study 2, participants did not show the moral self effect, and so it is impossible for us to make conclusions about whether this effect is due to similarity or identity – there was no observed effect for us to tease apart. Everett, Skorburg, & Savulescu (2020) Philosophical Psychology Post-Print 15 psychological change than when they lost their moral conscience, and marginally-but nonsignificantly more wrong to sacrifice the patient when they had lost their memories than when they had lost their moral conscience. When asked to make a categorical decision about which patient they had a moral duty to protect, significantly more participants said they had no moral duties to protect either patient in the moral condition compared to the control condition, though there was no difference between the morality and memories condition. Across all measures, participants felt their moral duties largely preserved towards someone who experienced no psychological change, yet more disrupted when the person changed, though the difference between memories and morals was not always significant. Overall, these empirical results show a clear link between perceived identity change and perceived moral duties, suggesting that it is not possible to entirely dismiss previous demonstrations of the moral self effect as just about similarity. This is to be expected, given the low likelihood that lay-people are spontaneously and intuitively activating subtle philosophical distinctions between e.g. quantitative and qualitative identity. Instead, we think, participants are likely to think about the self in terms of both identity and similarity, flexibly activating and focusing on either qualitative or quantitative identity in different contexts depending on the task at hand. But we also think that Starmans and Bloom's challenge can be resisted on conceptual grounds. In the first place, we are not sure that it is entirely possible to separate qualitative (similarity) from quantitative (personal) identity. Indeed, part of the reason that we have statutory limitations on prosecuting certain crimes does seem to be that even if the transgressor shares the same numerical identity, their qualitative similarity has dropped enough that the link of moral responsibility is severed (Mott, 2018; K. Tobia, 2016). Moreover, we are not sure that it is entirely possible to separate qualitative (similarity) from quantitative (personal) identity within prominent philosophical treatments, such as the psychological reductionist account of personal identity proposed by e.g., Parfit (1984). These accounts suggest that what matters is not the strict identity relation of memories between persons (e.g. where Person at Time-1 is either identical to the Person at Time-2, or they are different persons) but the degree of psychological connectedness. According to Parfit (1984), such psychological connectedness does include memories, but also psychological dispositions, attitudes, personality, preferences, and so on. This has elements of qualitative identity (a greater degree of psychological connectedness means that someone is more similar), but also quantitative identity, because it is the degree of psychological connectedness that allows us to identify a person at different times as the same person. Both of these points suggest that a strict division between qualitative identity (similarity) and quantitative (personal) identity is likely untenable. Starmans and Bloom may be right that previous findings are partly about similarity, but this does not mean they do not tell as anything about ordinary peoples' intuitions regarding personal identity, at least on a psychological continuity account. Limitations and Future Directions We have argued that previous findings cannot be explained solely in terms of similarity, but also that participants' responses are reflecting – at least partially – their intuitions about personal identity. In the present design it is impossible to entirely tease apart similarity from personal identity (to the extent that this is possible at all: see above discussion), and it would be interesting for future work to explore further the relative influence of moral changes on similarity and personal identity separately. Everett, Skorburg, & Savulescu (2020) Philosophical Psychology Post-Print 16 By focusing on perceived moral duties toward targets undergoing changes, our paper also raises a range of new questions about how different kinds of identity changes influence perceptions of the target's own moral responsibility and accountability. Imagine, for example, that prior to the brain transplant, the stranger has committed a crime. Presumably participants will hold the patient with the stranger's brain to be morally accountable for the crime, but would this be weaker when the patient loses their memories or moral conscience in the process of the transplant? Future work should explore these and related questions, which bring the practical import of judgements of identity change to the fore. Returning to more everyday matters, our results might explain why people regard patients with Alzheimer's Disease and other dementias as the same person, even when they have lost substantial memories. Provided their moral character remains intact, they are regarded as the same. Indeed, it is when a person's moral behavior changes with dementia that they are typically said to be "not themselves", not when they lose memory (and this, presumably, is why participants judged it as marginally more wrong to sacrifice the patient when they had lost their memories than when they had lost their moral conscience). 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