WEBVTT 99:59:59.999 --> 99:59:59.999 It's 1878. 99:59:59.999 --> 99:59:59.999 Sir Francis Galton gives a remarkable talk. 99:59:59.999 --> 99:59:59.999 He's speaking to the Anthropologic Instisitute of Great Britain and Ireland. 99:59:59.999 --> 99:59:59.999 Known for his pioneering work in human intelligence, 99:59:59.999 --> 99:59:59.999 Dalton is a brilliant polymath. 99:59:59.999 --> 99:59:59.999 He's an explorer, 99:59:59.999 --> 99:59:59.999 and antrhopologist, 99:59:59.999 --> 99:59:59.999 a sociologist, 99:59:59.999 --> 99:59:59.999 a psychologist, 99:59:59.999 --> 99:59:59.999 and a statistician. 99:59:59.999 --> 99:59:59.999 He's also a Eugenist. 99:59:59.999 --> 99:59:59.999 In this talk, 99:59:59.999 --> 99:59:59.999 he presents a new technique 99:59:59.999 --> 99:59:59.999 by which he can combine photographs and produce composite portraits. 99:59:59.999 --> 99:59:59.999 This technique could be used to characterize different types of people. 99:59:59.999 --> 99:59:59.999 Dalton thinks that if he combines photographs of violent criminals, 99:59:59.999 --> 99:59:59.999 he will discover the face of criminality. 99:59:59.999 --> 99:59:59.999 But to his surprise, 99:59:59.999 --> 99:59:59.999 the composite portrait that he produces 99:59:59.999 --> 99:59:59.999 is beautiful. 99:59:59.999 --> 99:59:59.999 Galton's surprising finding raises deep questions. 99:59:59.999 --> 99:59:59.999 What is beauty? 99:59:59.999 --> 99:59:59.999 Why do certain configurations of line and color and form excite us so? 99:59:59.999 --> 99:59:59.999 For most of human hisotiry, 99:59:59.999 --> 99:59:59.999 these questions have been approached using logic and speculation, 99:59:59.999 --> 99:59:59.999 but in the last few decades, 99:59:59.999 --> 99:59:59.999 scientists have addressed the question of beauty 99:59:59.999 --> 99:59:59.999 using ideas from evolutionary psychology and tools of neuroscience. 99:59:59.999 --> 99:59:59.999 We're beginning to glimpse the why and the how of beauty, 99:59:59.999 --> 99:59:59.999 at least in terms of what it means for the human face and form. 99:59:59.999 --> 99:59:59.999 And in the process, 99:59:59.999 --> 99:59:59.999 we're stumbling upon some surprises. 99:59:59.999 --> 99:59:59.999 When it comes to seeing beauty in each other, 99:59:59.999 --> 99:59:59.999 while this decision is certainly subjective for the individual, 99:59:59.999 --> 99:59:59.999 it's sculpted by factors that contribute to the survival of the group. 99:59:59.999 --> 99:59:59.999 Many experiments have shown 99:59:59.999 --> 99:59:59.999 that a few basic parameters contribute to what makes a face attractive. 99:59:59.999 --> 99:59:59.999 These include averaging, symmetry and the effects of hormones. 99:59:59.999 --> 99:59:59.999 And let's take each one of these in turn. 99:59:59.999 --> 99:59:59.999 Galton's finding 99:59:59.999 --> 99:59:59.999 that composite or average faces are typically more attractive 99:59:59.999 --> 99:59:59.999 than each individual face that contributes to the average 99:59:59.999 --> 99:59:59.999 has been replicated many times. 99:59:59.999 --> 99:59:59.999 This laboratory finding fits with many people's intuitions. 99:59:59.999 --> 99:59:59.999 Average faces represent the central tendencies of a group. 99:59:59.999 --> 99:59:59.999 People with mixed features represent different populations, 99:59:59.999 --> 99:59:59.999 and presumably harbor rare genetic diversity 99:59:59.999 --> 99:59:59.999 and adaptibility to the environment. 99:59:59.999 --> 99:59:59.999 Many people find mixed-race individuals attractive 99:59:59.999 --> 99:59:59.999 and inbred families less so. 99:59:59.999 --> 99:59:59.999 The second factor that contributes to beauty is symmetry. 99:59:59.999 --> 99:59:59.999 People generally find symmetic faces more attractive than asymmetic ones. 99:59:59.999 --> 99:59:59.999 Developmental abnormalities are often associated with asymmetries, 99:59:59.999 --> 99:59:59.999 and in plants, animal and humans, 99:59:59.999 --> 99:59:59.999 asymmetries often arise from parasitic infections. 99:59:59.999 --> 99:59:59.999 Symmetry it turns out, 99:59:59.999 --> 99:59:59.999 is also an indicator of health. 99:59:59.999 --> 99:59:59.999 In the 1930s, 99:59:59.999 --> 99:59:59.999 a man named MAximallian Fector Rowis 99:59:59.999 --> 99:59:59.999 recognized the importance of symmetry for beauty 99:59:59.999 --> 99:59:59.999 when he designed the beauty micrometer. 99:59:59.999 --> 99:59:59.999 With this device, 99:59:59.999 --> 99:59:59.999 he could measure minor, asymmetric flaws 99:59:59.999 --> 99:59:59.999 which he could then make up for with products he sold from his company, 99:59:59.999 --> 99:59:59.999 named brilliantly after himself: 99:59:59.999 --> 99:59:59.999 Max Factor, 99:59:59.999 --> 99:59:59.999 which as you know is one of the world's most famous brands for makeup. 99:59:59.999 --> 99:59:59.999 The third factor that contributes to facial attractiveness 99:59:59.999 --> 99:59:59.999 is the effect of hormones. 99:59:59.999 --> 99:59:59.999 And here, I need to apologize for confining my comments 99:59:59.999 --> 99:59:59.999 to heterosexual norms. 99:59:59.999 --> 99:59:59.999 But estrogen and testosterone play important roles 99:59:59.999 --> 99:59:59.999 in shaping features that we find attractive. 99:59:59.999 --> 99:59:59.999 Estrogen produces features that signal fertility. 99:59:59.999 --> 99:59:59.999 Men typically find woman attractive 99:59:59.999 --> 99:59:59.999 who have elements of both youth and maturity. 99:59:59.999 --> 99:59:59.999 A face that's too baby-like might mean that the girl is not yet fertile, 99:59:59.999 --> 99:59:59.999 so men find women attractive 99:59:59.999 --> 99:59:59.999 who have large eyes, full lips and narrow chins 99:59:59.999 --> 99:59:59.999 as indicators of youth, 99:59:59.999 --> 99:59:59.999 and high cheekbones as an indicator of maturity. 99:59:59.999 --> 99:59:59.999 Now, testosterone produces features that we regard as typically masculine. 99:59:59.999 --> 99:59:59.999 These include heavier brows, 99:59:59.999 --> 99:59:59.999 thinner cheeks 99:59:59.999 --> 99:59:59.999 and bigger, squared-off jaws. 99:59:59.999 --> 99:59:59.999 But here's a fascinating irony. 99:59:59.999 --> 99:59:59.999 In many species, 99:59:59.999 --> 99:59:59.999 if anything, 99:59:59.999 --> 99:59:59.999 testosterone suppresses the immune system. 99:59:59.999 --> 99:59:59.999 So the idea that testosterone-infused features are a fitness indicator 99:59:59.999 --> 99:59:59.999 doesn't really make a whole lot of sense. 99:59:59.999 --> 99:59:59.999 Here, the logic is turned on its head. 99:59:59.999 --> 99:59:59.999 Instead of a fitness indicator, 99:59:59.999 --> 99:59:59.999 scientists invoke a handicap principle. 99:59:59.999 --> 99:59:59.999 The most commonly cited example of a handicap 99:59:59.999 --> 99:59:59.999 is a peacock's tail. 99:59:59.999 --> 99:59:59.999 This beautiful but cumbersome tail doesn't exactly help the peacock 99:59:59.999 --> 99:59:59.999 avoid predators and approach peahens. 99:59:59.999 --> 99:59:59.999 Why should such an extravagant appendage evolve? 99:59:59.999 --> 99:59:59.999 Even Charles Darwin, 99:59:59.999 --> 99:59:59.999 in an 1860 letter to Asa Gray wrote 99:59:59.999 --> 99:59:59.999 that the sight of the peacock's tail made him physcially illl. 99:59:59.999 --> 99:59:59.999 He couldn't explain it with his theory of natural selection, 99:59:59.999 --> 99:59:59.999 and out of this frustration, 99:59:59.999 --> 99:59:59.999 he developed a theory of sexual selection. 99:59:59.999 --> 99:59:59.999 On this account, 99:59:59.999 --> 99:59:59.999 the display of the peacock's tail is about sexual enticement, 99:59:59.999 --> 99:59:59.999 and this enticement means that it's more likely 99:59:59.999 --> 99:59:59.999 that the peacock will mate and have offspring. 99:59:59.999 --> 99:59:59.999 Now, the modern twist on this display argument 99:59:59.999 --> 99:59:59.999 is that the peacock is also advertising its health to the peahen. 99:59:59.999 --> 99:59:59.999 Only especially fit organisms can afford to divert resources 99:59:59.999 --> 99:59:59.999 to maintaining such an extravagant appendage. 99:59:59.999 --> 99:59:59.999 Only espeically fit men can afford the price that testorone levies 99:59:59.999 --> 99:59:59.999 on their immune system. 99:59:59.999 --> 99:59:59.999 And by anaology, 99:59:59.999 --> 99:59:59.999 think of the fact that only very rich men can afford 99:59:59.999 --> 99:59:59.999 to pay more than $10,000 for a watch as a display of their financial fitness. 99:59:59.999 --> 99:59:59.999 Now, many people hear these kinds of evoulutionary claims 99:59:59.999 --> 99:59:59.999 and think they mean that we somehow are unconciously seeking mates 99:59:59.999 --> 99:59:59.999 who are healthy, 99:59:59.999 --> 99:59:59.999 and I htink this idea is probably not right. 99:59:59.999 --> 99:59:59.999 Teenagers and young adults are not exactly known for making decisions 99:59:59.999 --> 99:59:59.999 that are predicated on health concerns. 99:59:59.999 --> 99:59:59.999 But they don't have to be, 99:59:59.999 --> 99:59:59.999 and let me explain why. 99:59:59.999 --> 99:59:59.999 Imaging a population in which people have three different types of preferences: 99:59:59.999 --> 99:59:59.999 for green, for orange and for red. 99:59:59.999 --> 99:59:59.999 From their point of view, 99:59:59.999 --> 99:59:59.999 their preferences have nothing to do with health, 99:59:59.999 --> 99:59:59.999 they just like what they like. 99:59:59.999 --> 99:59:59.999 But if it were also the case 99:59:59.999 --> 99:59:59.999 that these preferences are associated with the different likelihood 99:59:59.999 --> 99:59:59.999 of producing offspring, 99:59:59.999 --> 99:59:59.999 let's say in a ration of three to two to one, 99:59:59.999 --> 99:59:59.999 then in the first generation, 99:59:59.999 --> 99:59:59.999 there would be three greens to two organges to one red, 99:59:59.999 --> 99:59:59.999 and in each subsequent generation, 99:59:59.999 --> 99:59:59.999 the proportion of greens increase 99:59:59.999 --> 99:59:59.999 so that intention rations 98 percent of this population has a green preference. 99:59:59.999 --> 99:59:59.999 Now, scientists coming in and sampling this population 99:59:59.999 --> 99:59:59.999 disover that green preferences are universal, 99:59:59.999 --> 99:59:59.999 so the point about this little abstract example 99:59:59.999 --> 99:59:59.999 is that while preferences for specific phsyical features 99:59:59.999 --> 99:59:59.999 can be arbitrary for the individual, 99:59:59.999 --> 99:59:59.999 if those features are hertiable 99:59:59.999 --> 99:59:59.999 and they are associated with a reproductive advangtage, 99:59:59.999 --> 99:59:59.999 over time, 99:59:59.999 --> 99:59:59.999 they become universal for the group. 99:59:59.999 --> 99:59:59.999 So what happens in the brain when we see beautiful people? 99:59:59.999 --> 99:59:59.999 Attractive faces activate parts of our visual cortex in the back of the brain. 99:59:59.999 --> 99:59:59.999 An area called the [fusiform gyrus] 99:59:59.999 --> 99:59:59.999 that is especially attuned to processing faces, 99:59:59.999 --> 99:59:59.999 and an adjacent area called the lateral occipidal complex 99:59:59.999 --> 99:59:59.999 that is especially attuned to processing objects. 99:59:59.999 --> 99:59:59.999 In addition, 99:59:59.999 --> 99:59:59.999 attractive faces activate parts of our reward and pleasure centers 99:59:59.999 --> 99:59:59.999 in the front and deep in the brain, 99:59:59.999 --> 99:59:59.999 and these include areas that have complicated names, 99:59:59.999 --> 99:59:59.999 like the ventral staiatum, 99:59:59.999 --> 99:59:59.999 the orber frontal cortex 99:59:59.999 --> 99:59:59.999 and the ventrimedial prefontol cortex. 99:59:59.999 --> 99:59:59.999 Our official brain that is attuned to processing faces 99:59:59.999 --> 99:59:59.999 interacts with our pleasure centers 99:59:59.999 --> 99:59:59.999 to underpin the experience of beauty. 99:59:59.999 --> 99:59:59.999 Amazingly, while we all engage with beauty, 99:59:59.999 --> 99:59:59.999 without our knowledge, 99:59:59.999 --> 99:59:59.999 beauty also engages us. 99:59:59.999 --> 99:59:59.999 Our brains respond to attractive faces even when we're not thinking about beauty. 99:59:59.999 --> 99:59:59.999 We conducted an experiement in which people saw a series of faces, 99:59:59.999 --> 99:59:59.999 and in one condition, 99:59:59.999 --> 99:59:59.999 they had to decide if a pair of faces were the same or a different person. 99:59:59.999 --> 99:59:59.999 Even in this condition, 99:59:59.999 --> 99:59:59.999 attractive faces drove neural activity robustly in their visual cortex 99:59:59.999 --> 99:59:59.999 despite the fact that they were thinking about a person's identity 99:59:59.999 --> 99:59:59.999 and not their beauty. 99:59:59.999 --> 99:59:59.999 Another group similarly found automatic responses to beauty 99:59:59.999 --> 99:59:59.999 within our pleasure centers. 99:59:59.999 --> 99:59:59.999 So taken together, 99:59:59.999 --> 99:59:59.999 these studies suggest that our brain automatically responds to beauty 99:59:59.999 --> 99:59:59.999 by linking vision and pleasure. 99:59:59.999 --> 99:59:59.999 These beauty detectors, 99:59:59.999 --> 99:59:59.999 it seems, 99:59:59.999 --> 99:59:59.999 ping ever time we see beauty regardless of whatever else 99:59:59.999 --> 99:59:59.999 we might be thinking. 99:59:59.999 --> 99:59:59.999 We also have a beauty is good stereotype embedded in the brain. 99:59:59.999 --> 99:59:59.999 Within the orber frontal cortex, 99:59:59.999 --> 99:59:59.999 there's overlapping neaural activity in response to beauty and to goodness, 99:59:59.999 --> 99:59:59.999 and this happens even when people aren't expllicitly thinking 99:59:59.999 --> 99:59:59.999 about beauty or goodness. 99:59:59.999 --> 99:59:59.999 Our brains seem to reflexively associate beauty and good. 99:59:59.999 --> 99:59:59.999 And this reflexive association may be the biologic trigger 99:59:59.999 --> 99:59:59.999 for the many social effects of beauty. 99:59:59.999 --> 99:59:59.999 Attractive people receive all kinds of advantages in life. 99:59:59.999 --> 99:59:59.999 They're regarded as more intelligent, 99:59:59.999 --> 99:59:59.999 more trustworthy, 99:59:59.999 --> 99:59:59.999 they're given higher pay and lesser punishments, 99:59:59.999 --> 99:59:59.999 even when such judgments are not warranted. 99:59:59.999 --> 99:59:59.999 These kinds of observations reveal beauty's ugly side. 99:59:59.999 --> 99:59:59.999 In my lab, 99:59:59.999 --> 99:59:59.999 we recently found that people with minor facial anomalies and disfigurements 99:59:59.999 --> 99:59:59.999 are regarded as less good, less kind, 99:59:59.999 --> 99:59:59.999 less intelligent, less competent and less hardworking. 99:59:59.999 --> 99:59:59.999 Unfortunately, we also have a disfigured-is-bad stereotype. 99:59:59.999 --> 99:59:59.999 This stereotype is probably exploited and magnified 99:59:59.999 --> 99:59:59.999 by images in the popular media 99:59:59.999 --> 99:59:59.999 in which facial disfigurement is often used as a shorthand 99:59:59.999 --> 99:59:59.999 to make someone a villianous character. 99:59:59.999 --> 99:59:59.999 We need to undersand these kinds of implicit biases 99:59:59.999 --> 99:59:59.999 if we are to overcome them, 99:59:59.999 --> 99:59:59.999 and aim for a society in which we treat people fairly, 99:59:59.999 --> 99:59:59.999 based on their behavior and not on the happenstance of their looks. 99:59:59.999 --> 99:59:59.999 Let me leave you with one final thought. 99:59:59.999 --> 99:59:59.999 Beauty is a work in progress. 99:59:59.999 --> 99:59:59.999 The so-called universal attributes of beauty 99:59:59.999 --> 99:59:59.999 were selected for -- 99:59:59.999 --> 99:59:59.999 during the almost two million years of the [plystascne?] 99:59:59.999 --> 99:59:59.999 Life was nasty, brutish and a very long time ago. 99:59:59.999 --> 99:59:59.999 The selection criteria for reproductive success from that time 99:59:59.999 --> 99:59:59.999 doesn't really apply today. 99:59:59.999 --> 99:59:59.999 For example, 99:59:59.999 --> 99:59:59.999 death by parasite is not one of the top ways that people die, 99:59:59.999 --> 99:59:59.999 at least not in the technologically-developed world. 99:59:59.999 --> 99:59:59.999 From antibiotics to surgery, 99:59:59.999 --> 99:59:59.999 birth control to invitrofertilization, 99:59:59.999 --> 99:59:59.999 the filters for reproductive success are being relaxed, 99:59:59.999 --> 99:59:59.999 and under these relaxed conditions, 99:59:59.999 --> 99:59:59.999 preference and trait combinations are free to drift 99:59:59.999 --> 99:59:59.999 and become more variable. 99:59:59.999 --> 99:59:59.999 Even as we are profoundly effecting our environment, 99:59:59.999 --> 99:59:59.999 modern medicine and technological innovation is profoundly effecting 99:59:59.999 --> 99:59:59.999 the very essence of what it means to look beautiful. 99:59:59.999 --> 99:59:59.999 The universal nature of beauty is changing 99:59:59.999 --> 99:59:59.999 even as we're changing the universe. 99:59:59.999 --> 99:59:59.999 Thank you. 99:59:59.999 --> 99:59:59.999 (Applause)