WEBVTT 00:00:00.000 --> 00:00:06.300 (intro music) 00:00:06.300 --> 00:00:07.740 Hi! I'm Nina Strohminger. 00:00:07.740 --> 00:00:10.740 I work at Yale University in the School of Management and 00:00:10.740 --> 00:00:12.400 the department a cognitive science. 00:00:12.400 --> 00:00:13.740 And I'm Shaun Nichols 00:00:13.740 --> 00:00:16.960 I'm a professor of philosophy at the University of Arizona. 00:00:16.960 --> 00:00:20.090 Imagine it's the not-distant future 00:00:20.090 --> 00:00:21.830 and you're in a car crash. 00:00:21.830 --> 00:00:24.410 Part of your brain is damaged in the crash, 00:00:24.410 --> 00:00:26.590 and the doctors have to replace it with a microchip. 00:00:26.600 --> 00:00:28.800 But the microchip is faulty, and it doesn't 00:00:28.800 --> 00:00:31.439 completely restore every part of your mind. 00:00:31.439 --> 00:00:34.790 One way it could malfunction is it could lead you to 00:00:34.790 --> 00:00:36.110 no longer be able to identify objects. 00:00:36.110 --> 00:00:39.800 This is called "visual object agnosia." 00:00:39.800 --> 00:00:43.110 Another malfunction the microchip is capable of producing 00:00:43.110 --> 00:00:45.740 is it removes all of your desires and interests: 00:00:45.740 --> 00:00:49.430 music you like, your hobbies, your goals for the future. 00:00:49.430 --> 00:00:52.500 The microchip can also lead to amnesia 00:00:52.500 --> 00:00:55.740 for all your experiences prior to the crash. 00:00:55.740 --> 00:00:59.210 Finally, the microchip could lead you to lose your moral compass, 00:00:59.210 --> 00:01:02.340 your ability to know the difference between right and wrong. 00:01:02.340 --> 00:01:05.360 For which of these injuries to your mind 00:01:05.360 --> 00:01:07.420 would your identity be the most altered? 00:01:07.420 --> 00:01:10.600 Philosophy has provided multiple conjectures 00:01:10.600 --> 00:01:12.429 about the answer to this kind of question. 00:01:12.429 --> 00:01:17.950 Some philosophers, like Bernard Williams, have suggested that biological continuity, 00:01:17.950 --> 00:01:22.030 having the same organism, is the most important part of identity. 00:01:22.030 --> 00:01:26.970 On this view, the aspect of the scenario that would alter your identity the most 00:01:26.970 --> 00:01:30.549 is the addition of the microchip to your brain, 00:01:30.549 --> 00:01:32.040 because that's changing the organismic properties. 00:01:32.040 --> 00:01:34.580 So it's not the changes to the psychological function that 00:01:34.580 --> 00:01:36.180 matter primarily in this case. 00:01:36.180 --> 00:01:38.820 It's the changes to the biology that matter. 00:01:38.820 --> 00:01:42.880 An alternative account is the collection of psychological traits, 00:01:42.880 --> 00:01:47.360 like personality traits and preferences, that that's the basis for identity. 00:01:47.360 --> 00:01:51.180 In particular, the mental features that most allow us to differentiate one 00:01:51.180 --> 00:01:52.860 person from another seem that they'd be 00:01:52.860 --> 00:01:56.219 likely candidates for being a critical part of personal identity. 00:01:56.219 --> 00:02:00.860 If that view is correct, then losing one's distinctive desires in memory should 00:02:00.860 --> 00:02:03.049 cause the greatest change to identity. 00:02:03.049 --> 00:02:05.180 Memory has traditionally been seen as 00:02:05.180 --> 00:02:08.110 playing an especially crucial role in personal identity. 00:02:08.110 --> 00:02:10.100 John Locke illustrates this idea with a 00:02:10.100 --> 00:02:13.150 thought experiment about a prince and a cobbler. 00:02:13.150 --> 00:02:17.790 Imagine the mind of a prince, containing all the prince's past experiences 00:02:17.799 --> 00:02:22.290 were to enter into, and replace, the Cobbler's memories and experiences. 00:02:22.290 --> 00:02:25.760 This new individual, is he the prince or the cobbler? 00:02:25.760 --> 00:02:29.489 Locke think the answer is really obvious: of course this is the prince! 00:02:29.489 --> 00:02:32.970 It's just that, now, the prince is inhabiting the body the cobbler. 00:02:32.970 --> 00:02:34.910 More recently, it's been suggested that 00:02:34.910 --> 00:02:37.570 morality is the most important part of identity. 00:02:37.570 --> 00:02:41.530 Cultural folklore provides indirect evidence in favor of this idea. 00:02:41.530 --> 00:02:44.200 For instance, in Western religious traditions, 00:02:44.200 --> 00:02:49.000 souls are seen not only as an entity that lends us our unique identity, 00:02:49.000 --> 00:02:51.340 but as the source of our conscience and moral action. 00:02:51.340 --> 00:02:56.280 However, the view that morality is key to identity has not traditionally been 00:02:56.280 --> 00:02:58.989 given much attention in philosophical circles. 00:02:58.989 --> 00:03:01.810 Despite the central position this question has 00:03:01.810 --> 00:03:03.849 occupied in philosophical debates, 00:03:03.849 --> 00:03:07.010 it's only been recently that philosophers began collecting data 00:03:07.010 --> 00:03:10.280 to show how people actually conceive of personal identity. 00:03:10.280 --> 00:03:14.000 Locke believed that memories were the most important part of identity, 00:03:14.000 --> 00:03:17.280 but does this map onto the way people actually think about identity? 00:03:17.280 --> 00:03:19.670 To find out, Shaun and I ran a study where 00:03:19.670 --> 00:03:22.509 we presented subjects with the microchip thought experiment. 00:03:22.509 --> 00:03:27.049 People in this study overwhelmingly report that loss of the moral faculty 00:03:27.049 --> 00:03:29.699 leads to the greatest change in someone's identity. 00:03:29.699 --> 00:03:32.159 The elimination of memories and desires 00:03:32.159 --> 00:03:35.590 also leads to a substantial change in identity, subjects report, 00:03:35.590 --> 00:03:39.339 just not as dramatic as one produced by a loss of moral capacities. 00:03:39.339 --> 00:03:41.729 Basic psychological processes, 00:03:41.729 --> 00:03:43.519 like object recognition, are not 00:03:43.519 --> 00:03:46.260 particularly important to identity permanence. 00:03:46.260 --> 00:03:48.389 And mere physical changes, such as 00:03:48.389 --> 00:03:50.790 installing the microchip that perfectly preserves 00:03:50.790 --> 00:03:54.930 mental function leads to the lowest degree of perceived identity change. 00:03:54.930 --> 00:03:57.949 When people consider what makes someone who they are, 00:03:57.949 --> 00:04:00.469 they place central importance on moral capacity. 00:04:00.469 --> 00:04:04.250 and this runs counter to perhaps the best-known theory of personal identity, 00:04:04.250 --> 00:04:07.750 Locke's memory criterion, according to which you're the same person 00:04:07.750 --> 00:04:11.819 just in case you remember having the experience of some past person. 00:04:11.819 --> 00:04:14.700 In other studies, we've found what people regard as most important about 00:04:14.700 --> 00:04:16.500 identity isn't really distinctiveness. 00:04:16.500 --> 00:04:18.108 It's the moral traits. 00:04:18.108 --> 00:04:22.490 And the moral traits that people have can be commonplace, and yet more critical to 00:04:22.490 --> 00:04:24.970 identity than traits that are more distinctive. 00:04:24.970 --> 00:04:30.240 So for instance, many people are nice, but losing that common trait is regarded as 00:04:30.240 --> 00:04:32.979 a much more dramatic insult to one's identity 00:04:32.979 --> 00:04:36.800 than losing some highly unusual preference, like a penchant for, 00:04:36.800 --> 00:04:40.490 I don't know, watermelon infused with beef juice. 00:04:40.490 --> 00:04:44.860 This study also illustrates the power of empirical data to shed light on 00:04:44.860 --> 00:04:46.850 age-old philosophical problems. 00:04:46.860 --> 00:04:49.330 While data can't provide a definitive answer 00:04:49.330 --> 00:04:52.780 to the metaphysical question of what ought identity to be, 00:04:52.780 --> 00:04:56.460 it can tell us how we think about our identities in everyday life.