WEBVTT 00:00:18.209 --> 00:00:23.710 These two Nazi scientists worked at the Dachau Concentration Camp 00:00:23.729 --> 00:00:25.459 during World War II. 00:00:26.250 --> 00:00:29.250 They were conducting an experiment 00:00:29.292 --> 00:00:33.667 to see how long a human being could survive in freezing water. 00:00:35.542 --> 00:00:37.168 Like good scientists, 00:00:37.250 --> 00:00:43.834 they took systematic measures including duration until death. 00:00:45.834 --> 00:00:49.876 Examples of human cruelty of this kind raise a big question. 00:00:50.501 --> 00:00:54.793 How is it possible to treat a person as a mere object? 00:00:56.918 --> 00:01:03.210 The traditional explanation for human cruelty is in terms of evil. 00:01:04.167 --> 00:01:09.376 I find the concept of evil unhelpful and unscientific. 00:01:09.918 --> 00:01:13.918 It implies that the person is possessed by some supernatural force. 00:01:14.709 --> 00:01:18.293 Even worse it's dangerously circular; 00:01:18.334 --> 00:01:22.293 if the definition of evil is the absence of good, 00:01:22.334 --> 00:01:24.208 then all we're really saying 00:01:24.209 --> 00:01:27.541 is he did something bad because he is not good. 00:01:27.542 --> 00:01:30.917 It hasn't really taken us any further forward. 00:01:31.959 --> 00:01:35.251 In contrast the concept of empathy, 00:01:35.292 --> 00:01:38.666 I'm going to argue is scientifically helpful; 00:01:38.667 --> 00:01:41.792 you can measure it, you can study it. 00:01:42.375 --> 00:01:48.458 Empathy has two distinct components -- cognitive and affective. 00:01:49.667 --> 00:01:52.209 Cognitive empathy is the ability 00:01:52.250 --> 00:01:55.001 to imagine someone else's thoughts and feelings; 00:01:55.042 --> 00:01:57.668 putting yourself into someone else's shoes. 00:01:57.684 --> 00:01:59.384 It's the recognition part. 00:02:00.584 --> 00:02:05.751 Affective empathy is the drive to respond with an appropriate emotion 00:02:05.751 --> 00:02:08.252 to what someone else is thinking or feeling. 00:02:08.959 --> 00:02:12.959 I'm going to argue that low affective empathy 00:02:13.000 --> 00:02:17.000 is a necessary factor to explain human cruelty. 00:02:18.209 --> 00:02:21.958 Empathy isn't all or none; it comes by degrees, 00:02:21.959 --> 00:02:25.001 and there a individual differences in it. 00:02:25.042 --> 00:02:28.751 So it gives rise to the empathy bell curve. 00:02:28.792 --> 00:02:31.875 Most of us are in the middle of this spectrum 00:02:31.921 --> 00:02:34.571 with average amounts of empathy. 00:02:34.584 --> 00:02:38.918 There are some people who have above average levels of empathy. 00:02:39.114 --> 00:02:40.494 But what are the factors 00:02:40.501 --> 00:02:44.501 that can lead an individual to have low empathy 00:02:45.125 --> 00:02:48.500 either temporarily or permanently? 00:02:48.542 --> 00:02:52.542 What are those social factors? What are those biological factors? 00:02:55.417 --> 00:02:59.251 One social factor is obedience to authority. 00:03:00.209 --> 00:03:04.750 The experiment by Stanley Milgram at Yale University showed 00:03:04.751 --> 00:03:08.874 that people are willing to administer electric shocks to someone 00:03:08.874 --> 00:03:10.334 to help them learn, 00:03:10.335 --> 00:03:13.584 if they're instructed to do so by an authority figure. 00:03:14.262 --> 00:03:16.035 This suggests that simply, 00:03:16.035 --> 00:03:20.334 following orders may be one factor that can erode our empathy. 00:03:22.209 --> 00:03:25.292 A second social factor is ideology. 00:03:26.542 --> 00:03:31.834 When the terrorists flew the planes into the World Trade Center on 9/11, 00:03:32.426 --> 00:03:34.006 We have to assume 00:03:34.026 --> 00:03:36.916 that they were in the grip of a strongly-held belief 00:03:36.918 --> 00:03:38.794 that they were doing the right thing. 00:03:40.876 --> 00:03:42.500 Of course, we don't know 00:03:42.501 --> 00:03:45.210 whether the terrorists who signed up for that action 00:03:45.233 --> 00:03:47.513 had low empathy to begin with, 00:03:48.210 --> 00:03:49.575 but it's possible 00:03:49.575 --> 00:03:52.859 that their ideological beliefs were another factor 00:03:52.859 --> 00:03:56.519 that could erode their empathy for their victims. 00:03:57.459 --> 00:04:01.960 A third social factor is in-group/out-group relations. 00:04:02.753 --> 00:04:07.463 In Rwanda, we saw one ethnic group used propaganda 00:04:07.493 --> 00:04:09.584 to stereotype the out-group; 00:04:09.616 --> 00:04:13.966 describing them as subhuman and as cockroaches. 00:04:14.784 --> 00:04:17.734 When we dehumanize a group as the enemy, 00:04:18.533 --> 00:04:22.743 we have the potential to lose our empathy; 00:04:23.600 --> 00:04:25.820 and we saw the catastrophic genocide 00:04:25.831 --> 00:04:27.141 that ensued. 00:04:29.317 --> 00:04:33.317 But none of these social factors can explain individuals like Ted Bundy. 00:04:34.706 --> 00:04:38.086 He started his adult career as a psychology student 00:04:38.114 --> 00:04:40.084 of the University of Washington 00:04:40.111 --> 00:04:43.021 where he volunteered on a telephone helpline 00:04:43.033 --> 00:04:46.553 and persuaded women to meet him. 00:04:46.569 --> 00:04:48.829 And over the successive years, 00:04:48.834 --> 00:04:54.084 he committed rape and murder of at least 30 women. 00:04:55.159 --> 00:04:58.369 We can assume that he had good cognitive empathy 00:04:58.398 --> 00:05:01.878 because he was able to deceive his victims, 00:05:02.384 --> 00:05:07.384 but that he lacked affective empathy - he just didn't care - 00:05:07.456 --> 00:05:10.456 and he lacked it in enduring ways. 00:05:12.203 --> 00:05:17.303 The evidence that psychopaths like Ted Bundy lack affective empathy 00:05:17.325 --> 00:05:20.203 comes from an experiment by James Blair 00:05:20.209 --> 00:05:22.793 that was conducted in Broadmoor Hospital. 00:05:22.829 --> 00:05:25.899 He showed psychopaths and a control group 00:05:25.928 --> 00:05:28.228 three different types of images, 00:05:28.248 --> 00:05:34.238 threatening images, neutral images, and images of people in distress. 00:05:34.980 --> 00:05:37.240 What he found was that the psychopaths 00:05:37.260 --> 00:05:41.435 only showed reduced physiological response 00:05:41.435 --> 00:05:44.445 when they saw the images of people in distress. 00:05:44.467 --> 00:05:48.467 So this suggests that they lacked affective empathy. 00:05:50.035 --> 00:05:54.755 People with autism have difficulties with cognitive empathy. 00:05:54.770 --> 00:05:57.880 They struggle to imagine other people's thoughts, 00:05:57.900 --> 00:06:01.870 their motives, their intentions, and their feelings. 00:06:01.873 --> 00:06:05.553 But people with autism don't tend to hurt other people; 00:06:05.569 --> 00:06:08.059 instead, they are confused by other people 00:06:08.073 --> 00:06:12.833 and withdraw socially, preferring the more predictable world of objects. 00:06:13.845 --> 00:06:17.394 People with autism have intact affective empathy 00:06:17.394 --> 00:06:19.864 because when they hear that somebody is suffering 00:06:19.864 --> 00:06:21.769 it upsets them. 00:06:22.937 --> 00:06:25.097 This leads us to imagine 00:06:25.122 --> 00:06:29.712 that people with autism and psychopaths are mirror opposites. 00:06:30.198 --> 00:06:34.198 The psychopath has good cognitive empathy - that's how they can deceive - 00:06:34.967 --> 00:06:37.627 but they have reduced affective empathy. 00:06:37.726 --> 00:06:41.256 People with autism have intact affective empathy, 00:06:41.278 --> 00:06:45.278 but struggle with cognitive empathy for neurological reasons. 00:06:48.062 --> 00:06:50.462 Psychopaths don't come out of nowhere. 00:06:50.494 --> 00:06:52.084 Many of them have shown 00:06:52.124 --> 00:06:55.774 antisocial behavior and delinquency in their teens. 00:06:56.375 --> 00:07:01.126 John Bowlby at the Tavistock Clinic in London studied delinquents and found 00:07:01.142 --> 00:07:06.212 that many of them had experienced emotional neglect in early childhood. 00:07:07.248 --> 00:07:11.808 He argued that the absence of parental love in early childhood 00:07:11.816 --> 00:07:14.836 is another factor that can erode your empathy. 00:07:17.338 --> 00:07:20.448 But we know that early experience can't be the whole story 00:07:20.469 --> 00:07:23.579 because not everyone who has a bad childhood 00:07:23.595 --> 00:07:25.275 loses their empathy. 00:07:25.792 --> 00:07:31.001 Avshalom Caspi at the Institute of Psychiatry in London showed 00:07:31.032 --> 00:07:35.553 that if you've experienced severe maltreatment in childhood 00:07:36.017 --> 00:07:38.947 that increases your risk of delinquency. 00:07:39.542 --> 00:07:42.709 But your risk of deliquency goes up even more 00:07:42.742 --> 00:07:47.162 if you also a carrier of one version of the MAO-A gene 00:07:47.763 --> 00:07:49.263 shown here in red; 00:07:49.763 --> 00:07:52.463 so genes and environment interact. 00:07:54.441 --> 00:07:56.601 Another biological factor 00:07:56.628 --> 00:08:01.738 that is associated with empathy levels is the hormone testosterone. 00:08:02.665 --> 00:08:06.405 In the fetus, testosterone shapes brain development. 00:08:06.905 --> 00:08:08.654 We've measured testosterone 00:08:08.684 --> 00:08:11.815 in the amniotic fluid that surrounds the baby 00:08:11.815 --> 00:08:15.945 in women who are having amniocentesis during pregnancy. 00:08:17.074 --> 00:08:21.964 We then wait for the baby to be born, and we follow up the children. 00:08:22.868 --> 00:08:25.728 When the children were eight years old, 00:08:25.748 --> 00:08:28.418 we asked them which word best describes 00:08:28.448 --> 00:08:31.618 what the person in the photo is thinking or feeling. 00:08:32.188 --> 00:08:35.467 Here the correct answer is he is interested in something. 00:08:36.020 --> 00:08:41.191 What we found was that the higher the level of fetal testosterone, 00:08:41.207 --> 00:08:44.668 the more difficulties the child was having 00:08:45.124 --> 00:08:47.604 at this test of cognitive empathy. 00:08:48.446 --> 00:08:53.846 How much empathy we show is a function of the empathy circuit; 00:08:53.861 --> 00:08:56.421 a network of regions in the brain. 00:08:57.070 --> 00:08:59.190 Here we can look at just two of them: 00:08:59.209 --> 00:09:04.220 in red, for left ventromedial prefrontal cortex, 00:09:04.667 --> 00:09:06.667 and in blue, the amygdala. 00:09:08.260 --> 00:09:10.940 This is Phineas Gage who suffered damage 00:09:10.940 --> 00:09:14.644 to his left ventromedial prefrontal cortex 00:09:14.644 --> 00:09:20.271 after dynamite blasted a metal rod up behind his eye and through his brain. 00:09:21.028 --> 00:09:25.308 Before the accident, he was described as a polite, considerate individual. 00:09:26.080 --> 00:09:29.190 After the accident, he was described as rude 00:09:29.210 --> 00:09:30.897 and no longer able to judge 00:09:30.907 --> 00:09:34.087 what was socially appropriate for different situations. 00:09:34.109 --> 00:09:36.479 He'd lost his cognitive empathy. 00:09:39.125 --> 00:09:43.528 Jean Decety at the University of Chicago used brain scanning 00:09:43.578 --> 00:09:45.859 - functional magnetic resonance imaging - 00:09:46.505 --> 00:09:49.075 to look at the teenage delinquent brain 00:09:49.099 --> 00:09:53.879 whilst they were watching films where somebody experiences pain 00:09:53.899 --> 00:09:59.250 such as when this piano player's fingers got crushed by the lid of the piano 00:09:59.266 --> 00:10:01.436 falling down on his fingers. 00:10:01.471 --> 00:10:05.981 What he found was that teenagers with delinquency didn't show 00:10:06.011 --> 00:10:09.141 the typical levels of activity in the amygdala -- 00:10:09.152 --> 00:10:12.382 part of the empathy circuit in the brain. 00:10:12.411 --> 00:10:15.921 But let's not forget the positive side of empathy. 00:10:16.420 --> 00:10:19.140 Most of us have enough empathy, 00:10:19.155 --> 00:10:22.595 and some people have high levels of empathy. 00:10:23.547 --> 00:10:26.907 When these two men formed a relationship 00:10:26.938 --> 00:10:30.408 based on mutual respect and on empathy, 00:10:30.433 --> 00:10:33.723 it let to the end of apartheid in South Africa. 00:10:34.859 --> 00:10:38.499 Empathy is vital for a healthy democracy; 00:10:39.077 --> 00:10:41.797 it ensures that we listen to different perspectives, 00:10:42.446 --> 00:10:46.836 we hear other people's emotions, and we also feel them. 00:10:47.527 --> 00:10:51.527 Indeed without empathy, democracy would not be possible. 00:10:54.292 --> 00:10:56.842 I met this two women in Cambridge this week 00:10:56.865 --> 00:10:58.315 when they came to visit. 00:10:59.292 --> 00:11:03.292 On the left is Siham, and she is a Palestinian woman; 00:11:04.023 --> 00:11:08.183 her brother was shot and killed by an Israeli bullet. 00:11:10.000 --> 00:11:14.501 On the right is Robi; she is an Israeli woman. 00:11:15.013 --> 00:11:18.303 Her son was killed by a Palestinian bullet. 00:11:19.730 --> 00:11:23.030 These two women have taken the courageous step 00:11:23.030 --> 00:11:26.694 of forming a relationship across the political divide. 00:11:27.529 --> 00:11:30.669 They haven't given in to the emotion of revenge 00:11:31.008 --> 00:11:34.078 which would simply perpetuate the cycle of violence. 00:11:34.434 --> 00:11:38.524 Instead, they've used their empathy to recognize that they both share 00:11:38.550 --> 00:11:44.280 the same sorrow, the same awful pain of having lost a loved one. 00:11:46.788 --> 00:11:52.948 Empathy is our most valuable natural resource for conflict resolution. 00:11:54.167 --> 00:11:57.209 We could wait for our political leaders 00:11:57.237 --> 00:12:00.247 to use empathy - and that would be refreshing - 00:12:00.274 --> 00:12:03.536 but actually, we could all use our empathy. 00:12:03.542 --> 00:12:06.535 As Siham and Robi told me, 00:12:06.536 --> 00:12:10.226 "The conflict won't stop until we empathize." 00:12:10.265 --> 00:12:11.545 Thank you. 00:12:11.571 --> 00:12:13.301 (Applause)