1 00:00:00 --> 00:00:01 2 00:00:01 --> 00:00:03 The following content is provided by MIT OpenCourseWare 3 00:00:03 --> 00:00:06 under a Creative Commons license. 4 00:00:06 --> 00:00:09 Additional information about out license at MIT 5 00:00:09 --> 00:00:16 OpenCourseWare in general is available at ocw.mit.edu. 6 00:00:16 --> 00:00:18 PROFESSOR: The topic for lecture for the next couple of 7 00:00:18 --> 00:00:25 days is going to be romantic love or mating behavior or the 8 00:00:25 --> 00:00:28 interaction thereof or something like that. 9 00:00:28 --> 00:00:32 And I just learned the Shakespeare Ensemble is 10 00:00:32 --> 00:00:36 doing Taming of the Shrew. 11 00:00:36 --> 00:00:37 When? 12 00:00:37 --> 00:00:40 AUDIENCE: The nights of Friday, Saturday and 13 00:00:40 --> 00:00:42 [UNINTELLIGIBLE PHRASE] 14 00:00:42 --> 00:00:44 PROFESSOR: Tonight, tomorrow night, and Saturday at? 15 00:00:44 --> 00:00:45 AUDIENCE: 8 o'clock. 16 00:00:45 --> 00:00:45 PROFESSOR: 8 o'clock. 17 00:00:45 --> 00:00:46 Where? 18 00:00:46 --> 00:00:47 AUDIENCE: Little Kresge Theater. 19 00:00:47 --> 00:00:48 PROFESSOR: Little Kresge Theater. 20 00:00:48 --> 00:00:51 We should probably assign it like as homework or 21 00:00:51 --> 00:00:53 something like that. 22 00:00:53 --> 00:00:56 But you can go after today's lecture. 23 00:00:56 --> 00:00:59 You can go and try to apply evolutionary psychological 24 00:00:59 --> 00:01:02 theory to Taming of the Shrew if you like. 25 00:01:02 --> 00:01:06 And you can tell Bianca how you liked it. 26 00:01:06 --> 00:01:09 All right, enough Shakespeare. 27 00:01:09 --> 00:01:12 Shakespeare shows up again maybe later today. 28 00:01:12 --> 00:01:16 29 00:01:16 --> 00:01:16 Shhh. 30 00:01:16 --> 00:01:23 31 00:01:23 --> 00:01:26 Let me tell you about Chris and Terry here who are 32 00:01:26 --> 00:01:28 having an argument. 33 00:01:28 --> 00:01:31 I realize this is sort of a working memory exercise, too. 34 00:01:31 --> 00:01:35 So you have to pay attention to the particular details here. 35 00:01:35 --> 00:01:39 So Chris and Terry are having an argument. 36 00:01:39 --> 00:01:43 They've been going together for about a year. 37 00:01:43 --> 00:01:47 They don't live together, they do sleep together. 38 00:01:47 --> 00:01:52 Chris accuses Terry-- so Chris accuses Terry-- of seeing 39 00:01:52 --> 00:01:54 someone else on the side. 40 00:01:54 --> 00:01:56 Terry doesn't want to talk about it. 41 00:01:56 --> 00:02:01 Chris says that Terry never wants to talk about anything. 42 00:02:01 --> 00:02:06 Terry shouts that well, maybe there is somebody else on the 43 00:02:06 --> 00:02:10 side and says, well it's not like there's been much 44 00:02:10 --> 00:02:13 activity in this relationship lately anyway. 45 00:02:13 --> 00:02:20 And Chris snorts that there's more to a relationship 46 00:02:20 --> 00:02:22 than just sex. 47 00:02:22 --> 00:02:24 All right, you got that? 48 00:02:24 --> 00:02:29 And you will have noticed, even Kristen-- who stayed up all 49 00:02:29 --> 00:02:33 night cheering the Red Sox-- will have noticed that Chris 50 00:02:33 --> 00:02:38 and Terry are deliberately ambiguous as to the 51 00:02:38 --> 00:02:41 sex of who is who. 52 00:02:41 --> 00:02:44 They could of course be the same sex. 53 00:02:44 --> 00:02:47 And that reminds me to say ahead a time, I'm going to talk 54 00:02:47 --> 00:02:51 almost exclusively for the next two days, next two lectures 55 00:02:51 --> 00:02:55 about heterosexual relationships. 56 00:02:55 --> 00:02:58 Lots of fascinating stuff to say about same sex 57 00:02:58 --> 00:03:01 relationships, like so many topics in introductory 58 00:03:01 --> 00:03:04 psych, it's just one I'm not going to get to. 59 00:03:04 --> 00:03:13 So if we assume that Chris and Terry are male and female, one 60 00:03:13 --> 00:03:16 of them is male and one of them is female. 61 00:03:16 --> 00:03:19 And I don't remember which side I was gestering too, so I don't 62 00:03:19 --> 00:03:20 remember-- was this Chris or Terry? 63 00:03:20 --> 00:03:21 AUDIENCE: Terry. 64 00:03:21 --> 00:03:22 PROFESSOR: That was Terry. 65 00:03:22 --> 00:03:23 This was Chris. 66 00:03:23 --> 00:03:31 OK, so how many people vote that Terry is the male person? 67 00:03:31 --> 00:03:34 How many vote that Chris is the male person? 68 00:03:34 --> 00:03:37 How many vote that I got lost in the details? 69 00:03:37 --> 00:03:38 I can't remember who's who anymore? 70 00:03:38 --> 00:03:41 All right, well quick review. 71 00:03:41 --> 00:03:43 Chris accuses Terry of seeing someone on the side. 72 00:03:43 --> 00:03:45 Terry doesn't want to talk about it. 73 00:03:45 --> 00:03:47 Chris says Terry never wants to talk. 74 00:03:47 --> 00:03:49 Terry shouts that there may be somebody on the side and there 75 00:03:49 --> 00:03:51 hasn't been much activity and Chris says there's more to 76 00:03:51 --> 00:03:54 a relationship than sex. 77 00:03:54 --> 00:03:56 How many vote Terry is male? 78 00:03:56 --> 00:03:59 How many vote Chris is male? 79 00:03:59 --> 00:04:03 Gee, there seems to be a fairly strong asymmetry there, which 80 00:04:03 --> 00:04:11 is capturing something of the cliche that man are just 81 00:04:11 --> 00:04:15 interested in sex and women are interested in commitment 82 00:04:15 --> 00:04:16 or something like that. 83 00:04:16 --> 00:04:22 This is sort of a cartoon version recognizing that-- 84 00:04:22 --> 00:04:24 actually, we sort of backed off what I was saying last time 85 00:04:24 --> 00:04:26 about talking about individual differences and now we're 86 00:04:26 --> 00:04:28 talking about on average. 87 00:04:28 --> 00:04:34 Again, recognizing that there's vast variations 88 00:04:34 --> 00:04:37 in relationships between men and women. 89 00:04:37 --> 00:04:41 Is there any truth to this sort of asymmetry? 90 00:04:41 --> 00:04:45 If there is, how in the world would you explain it? 91 00:04:45 --> 00:04:48 That's the job for today's lecture. 92 00:04:48 --> 00:04:51 Well, I mean, there's lots of anecdotal evidence. 93 00:04:51 --> 00:04:57 How about a little bit of data evidence from one of my 94 00:04:57 --> 00:05:03 favorite experiments in the annals of experiments that you 95 00:05:03 --> 00:05:06 can't see how they ever got it passed-- oh, does it say 96 00:05:06 --> 00:05:08 IRB on the handout? 97 00:05:08 --> 00:05:11 IRB stands for Institutional Review Board. 98 00:05:11 --> 00:05:13 You don't have to worry about that bit of jargon, but those 99 00:05:13 --> 00:05:17 are the people who look at experimental protocols 100 00:05:17 --> 00:05:21 and decide whether it's permissible to do this. 101 00:05:21 --> 00:05:25 So if you volunteered to be a subject in our lab-- please do, 102 00:05:25 --> 00:05:29 we need subjects, talk to Kristen-- anyway, if you do 103 00:05:29 --> 00:05:35 we'll have you sign a 7 page consent form because they're 104 00:05:35 --> 00:05:38 really worried about the damage we can do to you looking at 105 00:05:38 --> 00:05:41 little red and green bars on a computer screen. 106 00:05:41 --> 00:05:46 So you have to imagine how this experiment ever got passed the 107 00:05:46 --> 00:05:49 IRB, though it does seem like a good one for reality 108 00:05:49 --> 00:05:50 TV perhaps. 109 00:05:50 --> 00:05:54 Anyway, so here you are, you're wandering around on campus, and 110 00:05:54 --> 00:06:00 an attractive member of the opposite sex approaches you 111 00:06:00 --> 00:06:03 and asks you one of these 3 questions. 112 00:06:03 --> 00:06:06 I should note that I was explaining this to my wife this 113 00:06:06 --> 00:06:08 morning and she got confused and thought this was a 114 00:06:08 --> 00:06:10 multiple choice test. 115 00:06:10 --> 00:06:12 It's not a multiple choice test, which 116 00:06:12 --> 00:06:16 would be even weirder. 117 00:06:16 --> 00:06:20 So the percentages don't need to add up to 100. 118 00:06:20 --> 00:06:21 That's important. 119 00:06:21 --> 00:06:25 But this person comes up to you and asks you either-- says 120 00:06:25 --> 00:06:28 something to the effect of, I've seen you around campus 121 00:06:28 --> 00:06:33 and you're really an attractive person. 122 00:06:33 --> 00:06:35 Would you go on a date with me? 123 00:06:35 --> 00:06:36 That's question 1. 124 00:06:36 --> 00:06:40 Would you come back to my apartment with me or would 125 00:06:40 --> 00:06:41 you have sex with me? 126 00:06:41 --> 00:06:45 127 00:06:45 --> 00:06:51 What I can't find out is what happens after the subject 128 00:06:51 --> 00:06:54 gives an answer, right? 129 00:06:54 --> 00:06:57 130 00:06:57 --> 00:07:00 This is a quite famous experiment, but the original 131 00:07:00 --> 00:07:03 experiment is published in a very obscure journal and I 132 00:07:03 --> 00:07:07 don't actually have a copy of the article. 133 00:07:07 --> 00:07:10 So we've got these 3 questions. 134 00:07:10 --> 00:07:14 There's the date question, the apartment question, 135 00:07:14 --> 00:07:20 and the sex question. 136 00:07:20 --> 00:07:25 And so we'll plot percent yes here. 137 00:07:25 --> 00:07:30 OK, if you are a woman person, what do you think, what 138 00:07:30 --> 00:07:34 percentage of women said, yes, I'll go on a date with 139 00:07:34 --> 00:07:35 you would you think? 140 00:07:35 --> 00:07:37 AUDIENCE: 50%. 141 00:07:37 --> 00:07:38 PROFESSOR: What? 142 00:07:38 --> 00:07:39 PROFESSOR: 50% 143 00:07:39 --> 00:07:40 PROFESSOR: 50%. 144 00:07:40 --> 00:07:42 That sounded terribly authoritative. 145 00:07:42 --> 00:07:46 Is that because it's written down in the book or something? 146 00:07:46 --> 00:07:47 AUDIENCE: I read it. 147 00:07:47 --> 00:07:49 PROFESSOR: You read it. 148 00:07:49 --> 00:07:50 It's not in [? Blightman ?] 149 00:07:50 --> 00:07:50 is it? 150 00:07:50 --> 00:07:52 AUDIENCE: No, it's on the website. 151 00:07:52 --> 00:07:53 PROFESSOR: It's on the website. 152 00:07:53 --> 00:07:55 Oh, the articles on the website? 153 00:07:55 --> 00:07:57 AUDIENCE: Yeah. 154 00:07:57 --> 00:07:57 PROFESSOR: Wait a second. 155 00:07:57 --> 00:07:59 I thought I didn't find the original article. 156 00:07:59 --> 00:08:00 AUDIENCE: [UNINTELLIGIBLE] 157 00:08:00 --> 00:08:01 PROFESSOR: What? 158 00:08:01 --> 00:08:02 AUDIENCE: An article [UNINTELLIGIBLE]. 159 00:08:02 --> 00:08:03 PROFESSOR: Oh, OK. 160 00:08:03 --> 00:08:05 Well 50%. 161 00:08:05 --> 00:08:07 Thank you. 162 00:08:07 --> 00:08:09 163 00:08:09 --> 00:08:12 This-- whoops 50% doesn't go all the way up. 164 00:08:12 --> 00:08:13 OK, 50%. 165 00:08:13 --> 00:08:17 This kind of takes the guess work out of it a bit. 166 00:08:17 --> 00:08:20 AUDIENCE: I won't answer anymore. 167 00:08:20 --> 00:08:22 PROFESSOR: I thought we could find out if you memorized 168 00:08:22 --> 00:08:24 all the percentages. 169 00:08:24 --> 00:08:29 So all right, if you're not a good person who went and read 170 00:08:29 --> 00:08:33 everything on the website-- all right, how many women do you 171 00:08:33 --> 00:08:36 think were willing to go back to the guy's apartment? 172 00:08:36 --> 00:08:38 [INTERPOSING VOICES] 173 00:08:38 --> 00:08:39 PROFESSOR: 2, 9 sounds great. 174 00:08:39 --> 00:08:42 The average is about 6. 175 00:08:42 --> 00:08:45 So 50, 6. 176 00:08:45 --> 00:08:48 Number or percentage of women who said sure, I 177 00:08:48 --> 00:08:50 will have sex with you? 178 00:08:50 --> 00:08:50 AUDIENCE: 1. 179 00:08:50 --> 00:08:52 AUDIENCE: Zero. 180 00:08:52 --> 00:08:54 PROFESSOR: Zero would be a good, kshht. 181 00:08:54 --> 00:08:58 182 00:08:58 --> 00:09:05 Now the IRB or sort of the sequel issue here that you'd 183 00:09:05 --> 00:09:08 love to know the answer to is, how many times the guy got like 184 00:09:08 --> 00:09:11 punched or reported to the campus police or something. 185 00:09:11 --> 00:09:13 But now, look. 186 00:09:13 --> 00:09:14 Do I have any color chalk? 187 00:09:14 --> 00:09:17 No, we'll just have to go for hatched bars today. 188 00:09:17 --> 00:09:18 So that's the female data. 189 00:09:18 --> 00:09:23 190 00:09:23 --> 00:09:25 Let's start at the other end here. 191 00:09:25 --> 00:09:29 What percentage of guys approached by a woman who said, 192 00:09:29 --> 00:09:30 I think you're attractive. 193 00:09:30 --> 00:09:33 Would you like to have sex, said yes? 194 00:09:33 --> 00:09:35 AUDIENCE: 75. 195 00:09:35 --> 00:09:38 PROFESSOR: She said she wasn't going to be answering anymore. 196 00:09:38 --> 00:09:39 Yeah, OK. 197 00:09:39 --> 00:09:39 It's 75%. 198 00:09:39 --> 00:09:53 199 00:09:53 --> 00:09:56 It's also interesting to see what happens with the 200 00:09:56 --> 00:09:57 rest of the questions. 201 00:09:57 --> 00:10:02 If you ask, would you go back to the apartment with me that 202 00:10:02 --> 00:10:04 drops to about, I think, 67%. 203 00:10:04 --> 00:10:07 204 00:10:07 --> 00:10:13 And if you ask, would you go on a date with me it drops to 50. 205 00:10:13 --> 00:10:17 So, now look the world is full of interesting 206 00:10:17 --> 00:10:20 asymmetries in data. 207 00:10:20 --> 00:10:24 Even sex differences in say mathematical ability or 208 00:10:24 --> 00:10:25 something like that. 209 00:10:25 --> 00:10:30 Sex differences in most stuff look like this. 210 00:10:30 --> 00:10:34 There's a data point with an error bar and there's another 211 00:10:34 --> 00:10:38 data point with an error bar and you say, oh yeah, look. 212 00:10:38 --> 00:10:40 There's a significant sex difference if we run 213 00:10:40 --> 00:10:43 8.5 million subjects. 214 00:10:43 --> 00:10:46 You don't get data like this most of the time. 215 00:10:46 --> 00:10:49 This is like a huge asymmetry. 216 00:10:49 --> 00:10:53 So one interesting question is, why is this huge? 217 00:10:53 --> 00:10:56 And another interesting question is this apparently 218 00:10:56 --> 00:11:01 counter intuitive slope to the male data where you're 219 00:11:01 --> 00:11:03 more likely if you're a guy to say, oh sure. 220 00:11:03 --> 00:11:09 I'll have sex with you right now, but I don't actually want 221 00:11:09 --> 00:11:11 to go on a date with you. 222 00:11:11 --> 00:11:15 Which is on the face of it, perhaps a little odd. 223 00:11:15 --> 00:11:18 But we'll come back to try to explain that. 224 00:11:18 --> 00:11:21 There are multiple ways. 225 00:11:21 --> 00:11:25 So this is not some weird isolated data point where 226 00:11:25 --> 00:11:28 people just did a very odd-- it's an odd experiment. 227 00:11:28 --> 00:11:31 Here, this is the one that you really wonder about what the 228 00:11:31 --> 00:11:34 next sentence was, you know, hi. 229 00:11:34 --> 00:11:36 You're very attractive, would you have sex with me? 230 00:11:36 --> 00:11:37 Oh yes, sure. 231 00:11:37 --> 00:11:39 Just kidding. 232 00:11:39 --> 00:11:44 233 00:11:44 --> 00:11:49 It's a very odd experiment, but a very interesting one. 234 00:11:49 --> 00:11:51 Yes, Mara knows the answer to the rest of-- 235 00:11:51 --> 00:11:53 AUDIENCE: We have a question. 236 00:11:53 --> 00:11:55 Did they control for the attractiveness 237 00:11:55 --> 00:11:55 of the questioner? 238 00:11:55 --> 00:11:57 I mean, what if-- 239 00:11:57 --> 00:12:00 PROFESSOR: Well, the description-- my expert witness 240 00:12:00 --> 00:12:02 can probably tell me better because she's read this more 241 00:12:02 --> 00:12:05 recently apparently, the description I think is simply 242 00:12:05 --> 00:12:08 that the experimenter -- this experimenter's confederate is 243 00:12:08 --> 00:12:10 described as being attractive. 244 00:12:10 --> 00:12:11 AUDIENCE: Well, I'm just saying-- 245 00:12:11 --> 00:12:12 pROFESSOR: But look. 246 00:12:12 --> 00:12:14 Do the intuition. 247 00:12:14 --> 00:12:16 You can only do the real intuition for the sex that 248 00:12:16 --> 00:12:17 you happen to belong to. 249 00:12:17 --> 00:12:22 But ask yourself, really attractive guy comes up and 250 00:12:22 --> 00:12:24 says, would you like to have sex with me right now, do you 251 00:12:24 --> 00:12:27 think the point moves a lot off zero? 252 00:12:27 --> 00:12:37 And short of-- I don't know-- nonhuman woman, it's not clear 253 00:12:37 --> 00:12:39 how much that point moves either. 254 00:12:39 --> 00:12:42 255 00:12:42 --> 00:12:43 I don't know. 256 00:12:43 --> 00:12:45 And it's not one of these things. 257 00:12:45 --> 00:12:50 Also, by the way, I do not recommend you know when you go 258 00:12:50 --> 00:12:53 off into-- course 15 seems to be the place where they like to 259 00:12:53 --> 00:12:55 do survey experiments and stuff like that. 260 00:12:55 --> 00:12:58 I don't recommend this one as one to try because I really do 261 00:12:58 --> 00:13:01 think that it's hard to imagine how to do this without 262 00:13:01 --> 00:13:03 getting into serious trouble. 263 00:13:03 --> 00:13:05 Fascinating as the experiment is. 264 00:13:05 --> 00:13:09 Other efforts to get it the same point have been done in 265 00:13:09 --> 00:13:12 sort of more indirect fashion, so you can be your subject in 266 00:13:12 --> 00:13:17 this one, which was one where you were asked to rate a 267 00:13:17 --> 00:13:24 variety of events as being positive or negative-- 268 00:13:24 --> 00:13:26 effectively positive or negative-- if this happened. 269 00:13:26 --> 00:13:31 And the most salient one seems to me to be one where the 270 00:13:31 --> 00:13:36 description was you're on a crowded subway car, an 271 00:13:36 --> 00:13:42 attractive member of the sex to which you are attracted begins 272 00:13:42 --> 00:13:46 to surreptitiuosly touch you on the subway car. 273 00:13:46 --> 00:13:50 Is this a positive or a negative event? 274 00:13:50 --> 00:13:56 The answer in the data is women overwhelmingly say eww, that's 275 00:13:56 --> 00:13:58 kind of creepy and negative. 276 00:13:58 --> 00:14:00 This is not good. 277 00:14:00 --> 00:14:05 And guys fairly overwhelmingly say, yeah. 278 00:14:05 --> 00:14:09 What's the problem here? 279 00:14:09 --> 00:14:14 Again, you get a hugely asymmetrical result and what 280 00:14:14 --> 00:14:18 we want to do is try to account for that asymmetry. 281 00:14:18 --> 00:14:22 Now assuming that you have not been entirely comatose for the 282 00:14:22 --> 00:14:25 first half of the course you will recognize that the broad 283 00:14:25 --> 00:14:31 classes of explanation are going to be nature nurture 284 00:14:31 --> 00:14:34 kinds of things and of course, it's always a combination. 285 00:14:34 --> 00:14:39 In particular, today what I'm going to talk about is a 286 00:14:39 --> 00:14:43 biological account and that's the account coming out of 287 00:14:43 --> 00:14:45 evolutionary psychology. 288 00:14:45 --> 00:14:48 Evolutionary psychology, the application of evolutionary 289 00:14:48 --> 00:14:54 theory to the topics in psychology is very prevalent, 290 00:14:54 --> 00:14:56 very important these days. 291 00:14:56 --> 00:15:01 It gets applied to a huge range of topics, some of which it 292 00:15:01 --> 00:15:04 probably doesn't have much to say about. 293 00:15:04 --> 00:15:07 But if there's anything that it's got a lot to say about 294 00:15:07 --> 00:15:10 it's probably human mating behavior. 295 00:15:10 --> 00:15:12 296 00:15:12 --> 00:15:15 And so that's why I'll talk about evolutionary psychology 297 00:15:15 --> 00:15:18 in this particular context. 298 00:15:18 --> 00:15:20 This is not to say it's the only way of accounting for 299 00:15:20 --> 00:15:23 mating behavior, but it's a particularly-- I think, it's 300 00:15:23 --> 00:15:27 very hard to argue that these sort of biological forces don't 301 00:15:27 --> 00:15:33 have some shaping influence on the way that we select mates 302 00:15:33 --> 00:15:36 and I want to try cashing out that argument today. 303 00:15:36 --> 00:15:43 If you want to read more about it there are several-- I 304 00:15:43 --> 00:15:47 put reference to several books on the handout. 305 00:15:47 --> 00:15:51 All of which I put on there because they talk about the 306 00:15:51 --> 00:15:53 topic, but they're all good reads. 307 00:15:53 --> 00:15:56 My current favorite actually is the [? Bowmeister ?] 308 00:15:56 --> 00:15:57 and [? Tyce ?] 309 00:15:57 --> 00:15:57 one. 310 00:15:57 --> 00:16:00 It's less of one of the ones that's sort of been on the 311 00:16:00 --> 00:16:03 bestseller list, but it's a beautifully written 312 00:16:03 --> 00:16:09 book on this topic if you're interested. 313 00:16:09 --> 00:16:13 All right, so let's run down the basic evolutionary psych 314 00:16:13 --> 00:16:18 argument and then attempts to see how it might account for 315 00:16:18 --> 00:16:23 the sort of data that we see in this area. 316 00:16:23 --> 00:16:29 If you are operating within this sort of evolutionary 317 00:16:29 --> 00:16:32 framework your goal as an organism is to do what? 318 00:16:32 --> 00:16:34 AUDIENCE: Pass on the genes. 319 00:16:34 --> 00:16:35 PROFESSOR: Pass on your genes. 320 00:16:35 --> 00:16:37 You've got to propagate your genes in some fashion. 321 00:16:37 --> 00:16:40 322 00:16:40 --> 00:16:43 You want to get that genetic material into 323 00:16:43 --> 00:16:45 future generations. 324 00:16:45 --> 00:16:46 And how you going to do that? 325 00:16:46 --> 00:16:49 326 00:16:49 --> 00:16:53 Weren't you paying attention in high school? 327 00:16:53 --> 00:16:56 There are several ways, but sexual reproduction is 328 00:16:56 --> 00:16:59 considered perhaps the most direct of these. 329 00:16:59 --> 00:17:01 It's not the only one, by the way. 330 00:17:01 --> 00:17:08 It's important to point out that if you think that again, 331 00:17:08 --> 00:17:10 by the way, all of this stuff is presumably operating 332 00:17:10 --> 00:17:13 at a very unconscious implicit kind of level. 333 00:17:13 --> 00:17:19 Nobody assums that people are wandering around the dating 334 00:17:19 --> 00:17:21 scene saying, got to pass on my genes. 335 00:17:21 --> 00:17:23 How am I going to do that? 336 00:17:23 --> 00:17:30 But the forces, the forces that are shaping that behavior are 337 00:17:30 --> 00:17:37 within this viewpoint shaped by this drive to pass on genetic 338 00:17:37 --> 00:17:39 material into the next generation. 339 00:17:39 --> 00:17:42 You can also propagate your genes by taking 340 00:17:42 --> 00:17:46 care of your relations. 341 00:17:46 --> 00:17:53 So if you've got a brother or sister with kids, those kids 342 00:17:53 --> 00:17:57 are genetically related to you and if you nurture them, if you 343 00:17:57 --> 00:18:00 pay for their college education or something, they're not as 344 00:18:00 --> 00:18:02 genetically related to you as your own children, but they're 345 00:18:02 --> 00:18:04 genetically related to you. 346 00:18:04 --> 00:18:07 And so you can do the propagation thing indirectly 347 00:18:07 --> 00:18:11 rather than through just regular old-fashioned 348 00:18:11 --> 00:18:13 sexual reproduction. 349 00:18:13 --> 00:18:17 This, by the way, is one of the arguments offered by 350 00:18:17 --> 00:18:22 evolutionary psychologists for the persistence of same 351 00:18:22 --> 00:18:24 sex relationships. 352 00:18:24 --> 00:18:28 Same sex relationships are a problem from this evolutionary 353 00:18:28 --> 00:18:32 point of view because they don't lead to offspring, right? 354 00:18:32 --> 00:18:37 Whatever else is going on, they don't lead to offspring. 355 00:18:37 --> 00:18:40 I don't know if there's any data for it, perhaps because I 356 00:18:40 --> 00:18:45 haven't looked, but one of the arguments that has been put 357 00:18:45 --> 00:18:49 forward from time to time are things like oh, gay men 358 00:18:49 --> 00:18:52 make great uncles. 359 00:18:52 --> 00:18:54 They're not going to have kids of their own, but they take 360 00:18:54 --> 00:18:59 care of their sister's kids and that's why it's not selected 361 00:18:59 --> 00:19:05 out-- it's not selected against by evolution. 362 00:19:05 --> 00:19:11 In any case, sticking with this sort of mainline tail, you 363 00:19:11 --> 00:19:13 want to propagate your genes. 364 00:19:13 --> 00:19:17 Sexual reproduction is a good way to do it. 365 00:19:17 --> 00:19:22 Now the thing about sex is you get pregnant. 366 00:19:22 --> 00:19:26 Actually only 1/2 of you get pregnant. 367 00:19:26 --> 00:19:28 It was sort of an ambiguous sentence. 368 00:19:28 --> 00:19:31 This is 1/2 of you, plural, get pregnant. 369 00:19:31 --> 00:19:36 Not 1/2 of you as an individual get pregnant. 370 00:19:36 --> 00:19:39 You never know what people learn in high school. 371 00:19:39 --> 00:19:46 In any case, it is that fact, that's the key fact this story 372 00:19:46 --> 00:19:48 that produces the asymmetry. 373 00:19:48 --> 00:19:51 Women get pregnant, men don't get pregnant. 374 00:19:51 --> 00:19:52 Why is that important? 375 00:19:52 --> 00:19:58 Well, that's important because being pregnant ties you up for 376 00:19:58 --> 00:20:05 9 months, being pregnant for 9 months at a time greatly is a 377 00:20:05 --> 00:20:10 profound rate-limiting step on how many kids you can have. 378 00:20:10 --> 00:20:17 And then if you're a human and not a spider or 379 00:20:17 --> 00:20:18 something like that. 380 00:20:18 --> 00:20:22 Once the kid is born or hatched or whatever you 381 00:20:22 --> 00:20:23 still got a problem here. 382 00:20:23 --> 00:20:26 You want this little bundle of genes to do something for you 383 00:20:26 --> 00:20:28 in evolutionary terms, you got to keep it alive. 384 00:20:28 --> 00:20:30 So it's not just the 9 months. 385 00:20:30 --> 00:20:35 There's a long time, long term commitment to this little 386 00:20:35 --> 00:20:38 evolutionary project that you've gotten into. 387 00:20:38 --> 00:20:42 The same constraints do not necessarily apply to men. 388 00:20:42 --> 00:20:45 Certainly the rate-limiting step does not apply because in 389 00:20:45 --> 00:20:49 principle guys can go off and have a gazillion babies-- 390 00:20:49 --> 00:20:53 that's a technical term-- as long as they can find the 391 00:20:53 --> 00:20:55 requisite gazillion women. 392 00:20:55 --> 00:20:59 The rate-limiting step for man is just how many women can 393 00:20:59 --> 00:21:01 you successfully impregnate? 394 00:21:01 --> 00:21:03 395 00:21:03 --> 00:21:08 We're not talking in what is right in social, civilized 396 00:21:08 --> 00:21:10 world or something like that, right? 397 00:21:10 --> 00:21:11 But we're just talking about the biology of 398 00:21:11 --> 00:21:13 the situation here. 399 00:21:13 --> 00:21:16 The men don't get pregnant. 400 00:21:16 --> 00:21:20 If you get woman 1 pregnant today you can get woman 2 401 00:21:20 --> 00:21:22 pregnant tomorrow in principle. 402 00:21:22 --> 00:21:23 That's not true for the woman. 403 00:21:23 --> 00:21:26 If you are a woman and you get pregnant today you don't get to 404 00:21:26 --> 00:21:29 get pregnant again tomorrow. 405 00:21:29 --> 00:21:30 That doesn't work. 406 00:21:30 --> 00:21:35 So fundamental difference, the evolutionary psych argument is 407 00:21:35 --> 00:21:37 that this should produce fundamental differences 408 00:21:37 --> 00:21:38 in behavior. 409 00:21:38 --> 00:21:42 In particular, if your goal is to get as many successful 410 00:21:42 --> 00:21:46 bundles of genes into the next generation as possible guys 411 00:21:46 --> 00:21:49 should be inclined to have sex early and often with as many 412 00:21:49 --> 00:21:52 partners as possible because that's going to produce 413 00:21:52 --> 00:21:53 lots and lots of babies. 414 00:21:53 --> 00:21:57 Women should be looking for something more like a 415 00:21:57 --> 00:22:03 commitment because it's a lot easier to take care of this 416 00:22:03 --> 00:22:06 little bundle of joy if somebody else's helping out. 417 00:22:06 --> 00:22:10 Either helping take care of the kid or at the very least, 418 00:22:10 --> 00:22:13 providing resources for this. 419 00:22:13 --> 00:22:16 It's an expensive business raising a kid, not just an 420 00:22:16 --> 00:22:19 expensive business if your a nice middle class kid and 421 00:22:19 --> 00:22:22 you're expecting to go to MIT or something like that. 422 00:22:22 --> 00:22:23 It's an expensive business period. 423 00:22:23 --> 00:22:26 You gotta feed the kid, you gotta keep it warm, and so on. 424 00:22:26 --> 00:22:28 Resources are required. 425 00:22:28 --> 00:22:37 And it is in your interest as the woman to have guys around, 426 00:22:37 --> 00:22:41 at least a guy around who's going to provide resources. 427 00:22:41 --> 00:22:43 Now, you can make up other stories. 428 00:22:43 --> 00:22:47 You could make up a story that says it would be in the woman's 429 00:22:47 --> 00:22:51 interest to have multiple mates who are kept in some doubts 430 00:22:51 --> 00:22:58 about who the father is so that they all provide resource. 431 00:22:58 --> 00:23:01 That sounds funny, but there's no reason why that story and 432 00:23:01 --> 00:23:05 there are species where that seems to-- you can almost 433 00:23:05 --> 00:23:07 always find an animal where it works out. 434 00:23:07 --> 00:23:13 If humans were a polyandrous species, a species where 435 00:23:13 --> 00:23:19 females had multiple mates at the same time that would 436 00:23:19 --> 00:23:22 require explanation and you could try explaining 437 00:23:22 --> 00:23:23 it the same terms. 438 00:23:23 --> 00:23:31 As it turns out across cultures the pattern is either one male, 439 00:23:31 --> 00:23:35 one female or one male, several females. 440 00:23:35 --> 00:23:41 That there are much rarer instances of one female, many 441 00:23:41 --> 00:23:45 males in human populations. 442 00:23:45 --> 00:23:52 So the mainline story is that the constraints of biology are 443 00:23:52 --> 00:23:57 going to incline the population to a population of males who 444 00:23:57 --> 00:24:05 are interested in frequent sex and whenever. 445 00:24:05 --> 00:24:10 And women who are going to be looking for a mate who's 446 00:24:10 --> 00:24:12 willing to make some sort of commitment. 447 00:24:12 --> 00:24:18 Now is there any evidence for evolutionary forces, biological 448 00:24:18 --> 00:24:22 constraints on mate selection in humans? 449 00:24:22 --> 00:24:25 Quite apart from these questions about who 450 00:24:25 --> 00:24:26 wants sex and when. 451 00:24:26 --> 00:24:30 Is there any evidence for this at all? 452 00:24:30 --> 00:24:33 The answer is yes. 453 00:24:33 --> 00:24:37 If I give some examples it's sort of surprising that this 454 00:24:37 --> 00:24:41 was ever controversial. 455 00:24:41 --> 00:24:42 Well, let's give an example. 456 00:24:42 --> 00:24:46 For example, if you're looking for evidence that something has 457 00:24:46 --> 00:24:49 these sort of biological, evolutionary roots what you're 458 00:24:49 --> 00:24:53 looking for is something that is ubiquitous in 459 00:24:53 --> 00:24:55 human societies. 460 00:24:55 --> 00:25:02 You don't want something where it's deemed attractive in one 461 00:25:02 --> 00:25:05 population or desirable in one population and not in 462 00:25:05 --> 00:25:05 another population. 463 00:25:05 --> 00:25:08 That can be very culturally determined. 464 00:25:08 --> 00:25:12 So I don't know of much in the way of great evolutionary psych 465 00:25:12 --> 00:25:14 arguments in favor of which bits of your body 466 00:25:14 --> 00:25:17 should be pierced. 467 00:25:17 --> 00:25:20 That seems to be the sort of thing that some groups think 468 00:25:20 --> 00:25:23 this is attractive and some groups think that is attractive 469 00:25:23 --> 00:25:28 and yeah-- but across human cultures there is a consistent 470 00:25:28 --> 00:25:34 preference for mates who are young and healthy as opposed to 471 00:25:34 --> 00:25:36 mates who are old and sick. 472 00:25:36 --> 00:25:44 There is no place where the ideal of attractiveness is an 473 00:25:44 --> 00:25:46 old person with a disease. 474 00:25:46 --> 00:25:48 It just isn't the case. 475 00:25:48 --> 00:25:56 Now it almost sounds funny, but-- I got a house 476 00:25:56 --> 00:25:56 full of books. 477 00:25:56 --> 00:25:58 I like to collect books. 478 00:25:58 --> 00:26:02 It turns out that the books I like best are pretty old and 479 00:26:02 --> 00:26:06 diseased and that's not weird. 480 00:26:06 --> 00:26:09 That doesn't strike people as odd. 481 00:26:09 --> 00:26:12 You do need to explain, it doesn't take much work to 482 00:26:12 --> 00:26:15 explain why there's a preference for young, healthy 483 00:26:15 --> 00:26:17 mates over old diseased mates. 484 00:26:17 --> 00:26:19 If you think that this has something to do with a drive 485 00:26:19 --> 00:26:22 towards reproduction you're much more likely to reproduce 486 00:26:22 --> 00:26:24 successfully with a young, healthy make. 487 00:26:24 --> 00:26:27 488 00:26:27 --> 00:26:34 The reason that these topics have been controversial has 489 00:26:34 --> 00:26:37 less to do with the science of the situation or it has had 490 00:26:37 --> 00:26:40 less to do with the science of the situation than with the 491 00:26:40 --> 00:26:41 politics of the situation. 492 00:26:41 --> 00:26:48 It is possible, as in the IQ case to go from uncontroversial 493 00:26:48 --> 00:26:55 or fairly straightforward bits of science to undesirable or at 494 00:26:55 --> 00:26:59 least controversial conclusions in a more political realm. 495 00:26:59 --> 00:27:05 So the sorts of things if you agree, if you are forced by the 496 00:27:05 --> 00:27:09 data to say look, there's a whopping asymmetry between 497 00:27:09 --> 00:27:13 males and females in this area. 498 00:27:13 --> 00:27:18 It is perhaps-- the concern is-- that it's a slippery slope 499 00:27:18 --> 00:27:24 from here to saying well, it's OK to pay women less than men. 500 00:27:24 --> 00:27:27 The actual causal chain between this particular factoid in 501 00:27:27 --> 00:27:30 paying women less than men is not immediately obvious to me 502 00:27:30 --> 00:27:31 as I'm saying it right here. 503 00:27:31 --> 00:27:37 But the reason that this is politically controversial is 504 00:27:37 --> 00:27:41 because anything that acknowledges a difference, some 505 00:27:41 --> 00:27:45 sort of biological difference between say men and women can 506 00:27:45 --> 00:27:50 in principle be used as a defense for social inequalities 507 00:27:50 --> 00:27:54 that you may not find desirable. 508 00:27:54 --> 00:27:57 But that's really a separate question. 509 00:27:57 --> 00:28:00 The scientific question or the psychological question is 510 00:28:00 --> 00:28:00 are there differences? 511 00:28:00 --> 00:28:05 There certainly seem to be data differences and 512 00:28:05 --> 00:28:07 where did they come from? 513 00:28:07 --> 00:28:10 514 00:28:10 --> 00:28:13 There are other sort of universal preferences that seem 515 00:28:13 --> 00:28:22 to reflect this desire for a mate who is likely to be a good 516 00:28:22 --> 00:28:26 partner in reproduction. 517 00:28:26 --> 00:28:29 What is it that makes a face attractive? 518 00:28:29 --> 00:28:35 Well, one of the things that is attractive is facial symmetry. 519 00:28:35 --> 00:28:42 That all else being equal it's considered to be better-- 520 00:28:42 --> 00:28:44 you're consider to be more attractive-- a face is rated as 521 00:28:44 --> 00:28:46 more attractive if it's symmetrical than if 522 00:28:46 --> 00:28:47 it's asymmetrical. 523 00:28:47 --> 00:28:49 Why is that? 524 00:28:49 --> 00:28:53 Most of the things that are likely to produce noticeable 525 00:28:53 --> 00:29:02 asymmetries in the face are things that suggest either a 526 00:29:02 --> 00:29:06 genetic deformity of some sort or an accident. 527 00:29:06 --> 00:29:10 528 00:29:10 --> 00:29:12 Neither of them are going to be great advertisements 529 00:29:12 --> 00:29:16 for reproductive success. 530 00:29:16 --> 00:29:21 Imagine somebody with half a face, you know intuitively that 531 00:29:21 --> 00:29:24 either you're watching a sci-fi movie or there's something 532 00:29:24 --> 00:29:27 fundamentally wrong here. 533 00:29:27 --> 00:29:31 Oh, what is an attractive face in general is an interesting-- 534 00:29:31 --> 00:29:33 I didn't put all those references on the handout. 535 00:29:33 --> 00:29:35 There's an interesting literature on what makes an 536 00:29:35 --> 00:29:40 attractive face that is worth a little side note. 537 00:29:40 --> 00:29:49 538 00:29:49 --> 00:29:50 You could have two theories. 539 00:29:50 --> 00:29:53 One theory would be attractive is one end of a scale that 540 00:29:53 --> 00:29:56 runs from ugly to gorgeous. 541 00:29:56 --> 00:29:59 That all those hollywood actors and actresses are pegged out 542 00:29:59 --> 00:30:01 here on the gorgeous end of some scale. 543 00:30:01 --> 00:30:04 544 00:30:04 --> 00:30:12 The alternative theory is that it is average faces-- that an 545 00:30:12 --> 00:30:16 average face is what's normal, is what's deemed attractive. 546 00:30:16 --> 00:30:19 547 00:30:19 --> 00:30:21 The original evidence for this comes from a photographic 548 00:30:21 --> 00:30:24 technique where what you did was you took a whole bunch of 549 00:30:24 --> 00:30:29 photographs and superimposed them to make a composite face 550 00:30:29 --> 00:30:31 and you found that those were rated as more attractive than 551 00:30:31 --> 00:30:35 individual faces as a whole. 552 00:30:35 --> 00:30:39 And this was being done by clever techniques back-- 553 00:30:39 --> 00:30:43 oh, I think in early part of the 20th century. 554 00:30:43 --> 00:30:46 And it's gotten a lot easier now that we've got computers 555 00:30:46 --> 00:30:48 to do these sort of things. 556 00:30:48 --> 00:30:52 The difficulty, one of the things that made this research 557 00:30:52 --> 00:30:55 a little tricky is that one thing that averaging faces 558 00:30:55 --> 00:30:58 does is it does wonders for your complexion. 559 00:30:58 --> 00:31:03 560 00:31:03 --> 00:31:06 Everybody's nose is in more or less the same place, but 561 00:31:06 --> 00:31:07 everybody's zit is not. 562 00:31:07 --> 00:31:11 And so if you average 100 faces you get people with gorgeous 563 00:31:11 --> 00:31:14 complexions and there's some part of that effect that just 564 00:31:14 --> 00:31:17 comes from the fact that they look like they had 565 00:31:17 --> 00:31:19 really healthy skin. 566 00:31:19 --> 00:31:22 It's a debate that jumps back and forth, if you turn out to 567 00:31:22 --> 00:31:25 be deeply interested in what makes a face attractive send 568 00:31:25 --> 00:31:27 me a note, I'll send you the reference since I see I didn't 569 00:31:27 --> 00:31:30 put them on the handout. 570 00:31:30 --> 00:31:33 We can ask for a couple of other things that suggests 571 00:31:33 --> 00:31:36 these universals across human populations. 572 00:31:36 --> 00:31:43 573 00:31:43 --> 00:31:45 What's more desirable in a mate? 574 00:31:45 --> 00:31:48 Richer or poorer? 575 00:31:48 --> 00:31:49 AUDIENCE: Richer. 576 00:31:49 --> 00:31:52 PROFESSOR: Richer, that's easy enough. 577 00:31:52 --> 00:31:56 Is that preference the same for men and women? 578 00:31:56 --> 00:31:59 Who's more interested in finding-- I'll tell you the 579 00:31:59 --> 00:32:03 answer-- it's not the same, how many vote that it's men 580 00:32:03 --> 00:32:06 who are more interested in finding a wealthy mate? 581 00:32:06 --> 00:32:08 How many vote that it's women? 582 00:32:08 --> 00:32:13 You got the right intuition and the evolutionary psych story 583 00:32:13 --> 00:32:15 there is the resource story. 584 00:32:15 --> 00:32:22 That what you're looking for is evidence of resource. 585 00:32:22 --> 00:32:27 Is this guy going to help me feed all those hundreds of 586 00:32:27 --> 00:32:31 babies that he thinks we're going to have? 587 00:32:31 --> 00:32:39 And this is also presumed to be-- why is it that driving, 588 00:32:39 --> 00:32:43 cruising around town in the fancy car, you know 589 00:32:43 --> 00:32:44 what's that about? 590 00:32:44 --> 00:32:47 That's a peacock tail effect. 591 00:32:47 --> 00:32:50 I think I already described the peacock tail effect 592 00:32:50 --> 00:32:51 earlier in the course. 593 00:32:51 --> 00:32:56 The idea is I'm showing off my resources, I've got so much 594 00:32:56 --> 00:32:58 money that I can buy this stupid car. 595 00:32:58 --> 00:33:05 My hubcaps cost more than your house, which is why 596 00:33:05 --> 00:33:08 you want to mate with me. 597 00:33:08 --> 00:33:11 This is presumed to be the way that they-- OK, how 598 00:33:11 --> 00:33:14 about age of spouse? 599 00:33:14 --> 00:33:17 Or age of mate? 600 00:33:17 --> 00:33:23 On average, if you are a male, you want a-- and this is very 601 00:33:23 --> 00:33:27 importantly on average, because it's not to say, well, let's 602 00:33:27 --> 00:33:29 get the data point first. 603 00:33:29 --> 00:33:33 If you're a male, on average how many people vote that you 604 00:33:33 --> 00:33:37 were looking for a mate who is-- well, this is a 3 605 00:33:37 --> 00:33:39 alternative forced choice, you got to vote for one of them: 606 00:33:39 --> 00:33:41 little older, exactly the same age, little younger. 607 00:33:41 --> 00:33:44 How many vote for little older? 608 00:33:44 --> 00:33:47 How many vote for just the same age? 609 00:33:47 --> 00:33:50 How many vote for a little younger? 610 00:33:50 --> 00:33:54 OK, got that intuition right. 611 00:33:54 --> 00:34:00 So males on average, in culture after culture seek mates 612 00:34:00 --> 00:34:01 who are a little younger. 613 00:34:01 --> 00:34:03 The amount varies culturally. 614 00:34:03 --> 00:34:06 In some cultures it's significantly younger. 615 00:34:06 --> 00:34:10 In some cultures it only a couple of years, but it is 616 00:34:10 --> 00:34:15 across cultures younger. 617 00:34:15 --> 00:34:18 OK, so the point I was going to make before is you're sitting 618 00:34:18 --> 00:34:25 there saying, my girlfriend is like 2 years older than me. 619 00:34:25 --> 00:34:28 This does not mean that you are some sort of genetic misfit. 620 00:34:28 --> 00:34:33 It means that we're back to talking about the mean value 621 00:34:33 --> 00:34:39 and all of these things have a distribution around them. 622 00:34:39 --> 00:34:46 It would be considered odd if your choice in mates was, I 623 00:34:46 --> 00:34:50 only date women who are 60 years older than me. 624 00:34:50 --> 00:34:54 That would be considered unusual, but that should be 625 00:34:54 --> 00:34:56 way, way out on one tail of it. 626 00:34:56 --> 00:34:59 But typically, the mean of that distribution lies 627 00:34:59 --> 00:35:00 a little younger. 628 00:35:00 --> 00:35:03 OK, why is that the case? 629 00:35:03 --> 00:35:05 If you're following this evolutionary psych story, why 630 00:35:05 --> 00:35:10 do males seek females who are slightly younger? 631 00:35:10 --> 00:35:11 AUDIENCE: They can have more babies. 632 00:35:11 --> 00:35:15 PROFESSOR: More babies, right. 633 00:35:15 --> 00:35:18 The males may not be limited in principle by the same 634 00:35:18 --> 00:35:20 rate-limiting step, but if you're in a culture that's 635 00:35:20 --> 00:35:25 going to limit you to 1 woman you better get 1 woman 636 00:35:25 --> 00:35:29 who's going to produced the maximum number of babies. 637 00:35:29 --> 00:35:32 So you better start young. 638 00:35:32 --> 00:35:37 So, if you are a woman, same multiple choice. 639 00:35:37 --> 00:35:41 If you are a women, the average-- across cultures women 640 00:35:41 --> 00:35:44 prefer-- how many vote that women prefer males who 641 00:35:44 --> 00:35:46 are slightly older? 642 00:35:46 --> 00:35:49 Exactly the same age? 643 00:35:49 --> 00:35:51 Slightly younger? 644 00:35:51 --> 00:35:52 You got the right intuition. 645 00:35:52 --> 00:35:54 Again, it's very convenient that this is the 646 00:35:54 --> 00:35:54 way it works out. 647 00:35:54 --> 00:36:00 It's really bad news if everybody wants younger mates. 648 00:36:00 --> 00:36:02 That doesn't work well. 649 00:36:02 --> 00:36:06 But actually, we'll come back to that in the next lecture. 650 00:36:06 --> 00:36:10 I'll just put that out there as a problem to solve. 651 00:36:10 --> 00:36:17 Everybody does want to max out on the attractive, rich 652 00:36:17 --> 00:36:22 gorgeous thing, but most of us aren't going to get that. 653 00:36:22 --> 00:36:24 654 00:36:24 --> 00:36:28 It's one male to one female roughly speaking. 655 00:36:28 --> 00:36:32 We can't all have that person, it just isn't 656 00:36:32 --> 00:36:33 going to work well. 657 00:36:33 --> 00:36:36 So we'll have to solve that next week. 658 00:36:36 --> 00:36:41 OK, why do females want males who are slightly older? 659 00:36:41 --> 00:36:43 AUDIENCE: Maturity. 660 00:36:43 --> 00:36:44 PROFESSOR: Maturity-- good luck. 661 00:36:44 --> 00:36:51 662 00:36:51 --> 00:36:56 The evolutionary psych argument is the resource argument. 663 00:36:56 --> 00:36:59 I'm sure maturity doesn't hurt either, but it's 664 00:36:59 --> 00:37:01 the resource argument. 665 00:37:01 --> 00:37:05 A guy has had a chance to accumulate more resource 666 00:37:05 --> 00:37:08 if he's a little older. 667 00:37:08 --> 00:37:11 And so you've got these endless-- sometimes, literally 668 00:37:11 --> 00:37:16 endless-- big, thick 19th century romance novels that you 669 00:37:16 --> 00:37:21 read in English lit at some point where he loves her but 670 00:37:21 --> 00:37:24 they can't get together for 800 pages because he's got to go 671 00:37:24 --> 00:37:27 out and collect resource in some fashion until he can come 672 00:37:27 --> 00:37:35 back and show daddy that he can support the daughter. 673 00:37:35 --> 00:37:37 The alternative version of the 19th century romance is the 674 00:37:37 --> 00:37:43 interview where daddy asks, how much money your daddy left you. 675 00:37:43 --> 00:37:47 Oh, yes, I have a thousand pounds. 676 00:37:47 --> 00:37:49 They're all English novels. 677 00:37:49 --> 00:37:52 A thousand pounds a year in the funds or something like that. 678 00:37:52 --> 00:37:53 That's resource, that's good. 679 00:37:53 --> 00:37:56 680 00:37:56 --> 00:37:58 Oh, there's one exception. 681 00:37:58 --> 00:38:05 There is a population of males who seeks slightly older women. 682 00:38:05 --> 00:38:07 Who is that population? 683 00:38:07 --> 00:38:08 [?___AUDIENCE:__ _Teenagers.___?] 684 00:38:08 --> 00:38:12 PROFESSOR: Exactly. 685 00:38:12 --> 00:38:16 There's this cruel sick chortle that we just got from-- all 686 00:38:16 --> 00:38:18 the answers given to that were by women. 687 00:38:18 --> 00:38:24 All of whom were snickering about it, which is harsh. 688 00:38:24 --> 00:38:27 But it's teenage males, particularly young teenage 689 00:38:27 --> 00:38:33 males who develop crushes on slightly older or maybe 690 00:38:33 --> 00:38:35 quite a bit older women. 691 00:38:35 --> 00:38:36 Why? 692 00:38:36 --> 00:38:38 What's that about? 693 00:38:38 --> 00:38:39 AUDIENCE: [UNINTELLIGIBLE] 694 00:38:39 --> 00:38:40 AUDIENCE: They're fertile. 695 00:38:40 --> 00:38:42 PROFESSOR: They're fertile, exactly. 696 00:38:42 --> 00:38:47 Now, I mean, the kid doesn't know this. 697 00:38:47 --> 00:38:49 Oh, I think I'd better fall in love with somebody 698 00:38:49 --> 00:38:50 who's fertile. 699 00:38:50 --> 00:38:53 700 00:38:53 --> 00:38:55 That's presumably not what's operating at any sort of 701 00:38:55 --> 00:39:02 conscious level here, but if evolutionary forces drive you 702 00:39:02 --> 00:39:08 to look for a mate who's going to be fertile and you're an 703 00:39:08 --> 00:39:13 early adolescent male, 9-year-old girls are not 704 00:39:13 --> 00:39:16 the population of choice. 705 00:39:16 --> 00:39:22 And you may notice that even the example gives you a sort 706 00:39:22 --> 00:39:24 of a eww kind of feeling. 707 00:39:24 --> 00:39:27 We have a sort of a gut, built in reaction that there are some 708 00:39:27 --> 00:39:31 relationships that are OK and some relationships 709 00:39:31 --> 00:39:32 that are odd. 710 00:39:32 --> 00:39:40 And so relationships and in particular, relationships-- 711 00:39:40 --> 00:39:43 guys can go and pursue fertile females. 712 00:39:43 --> 00:39:44 That's OK. 713 00:39:44 --> 00:39:47 That can be shown in the airline movie. 714 00:39:47 --> 00:39:50 Again, we don't have the airline movie, the headline 715 00:39:50 --> 00:39:56 comes up the search for the fertile woman, but ask yourself 716 00:39:56 --> 00:39:59 who it is-- who romantic comedies are about? 717 00:39:59 --> 00:40:04 You wouldn't put a movie on the airlines for family consumption 718 00:40:04 --> 00:40:08 about some guys unrequited passion for a 9-year-old girl. 719 00:40:08 --> 00:40:10 It would seem icky. 720 00:40:10 --> 00:40:12 That there's something wrong there. 721 00:40:12 --> 00:40:16 722 00:40:16 --> 00:40:17 Why? 723 00:40:17 --> 00:40:20 Presumably this has something to do with the same 724 00:40:20 --> 00:40:23 sort of forces. 725 00:40:23 --> 00:40:33 OK, so let's move on a bit to this, elaborate on this 726 00:40:33 --> 00:40:37 issue a bit, who should be faithful in relations? 727 00:40:37 --> 00:40:39 Who should cheat? 728 00:40:39 --> 00:40:42 So let's start with guys. 729 00:40:42 --> 00:40:46 Now recognize here, by the way, that we are talking again, 730 00:40:46 --> 00:40:50 within the context of this evolutionary psych viewpoint. 731 00:40:50 --> 00:40:55 We are not saying who should cheat in your relationship 732 00:40:55 --> 00:40:58 right now with the person sitting next to you or 733 00:40:58 --> 00:40:58 something like that. 734 00:40:58 --> 00:41:01 Or who does society say it's OK to cheat with. 735 00:41:01 --> 00:41:05 But in terms of this theory about evolutionary forces 736 00:41:05 --> 00:41:09 working on mate selection, who should have an evolutionary 737 00:41:09 --> 00:41:10 drive to cheat? 738 00:41:10 --> 00:41:11 Should guys? 739 00:41:11 --> 00:41:12 AUDIENCE: Yeah. 740 00:41:12 --> 00:41:13 PROFESSOR: Yeah, right. 741 00:41:13 --> 00:41:16 That's a pretty straightforward argument. 742 00:41:16 --> 00:41:20 That if you can get away with it, if you can have a few no 743 00:41:20 --> 00:41:24 cost babies somewhere-- great. 744 00:41:24 --> 00:41:27 You've done your evolutionary work. 745 00:41:27 --> 00:41:30 Look if we switched to a different context of cultural, 746 00:41:30 --> 00:41:35 civilized world kind of you may be a jerk, but you're an 747 00:41:35 --> 00:41:39 evolutionary successful jerk. 748 00:41:39 --> 00:41:42 OK, how about women? 749 00:41:42 --> 00:41:47 Should women be unfaithful and play around? 750 00:41:47 --> 00:41:49 AUDIENCE: Yes. 751 00:41:49 --> 00:41:51 PROFESSOR: OK, yes argument. 752 00:41:51 --> 00:41:52 What's the yes argument? 753 00:41:52 --> 00:41:55 Again, from an evolutionary point of view. 754 00:41:55 --> 00:41:57 AUDIENCE: Like a stronger mate. 755 00:41:57 --> 00:41:58 PROFESSOR: Yeah, you might get a stronger mate. 756 00:41:58 --> 00:42:02 You're hedging your genetic bets. 757 00:42:02 --> 00:42:09 If you are going to link up with this guy, maybe he turns 758 00:42:09 --> 00:42:11 out to be a genetic dud. 759 00:42:11 --> 00:42:15 If you just have your 18 babies with him you 760 00:42:15 --> 00:42:18 know, how good is that? 761 00:42:18 --> 00:42:23 But if you spread it around a bit, your genes are the same 762 00:42:23 --> 00:42:25 in all cases, who cares? 763 00:42:25 --> 00:42:27 You're always get your half of the package. 764 00:42:27 --> 00:42:30 And so you might as well mix it up a bit and so 765 00:42:30 --> 00:42:32 that's the yes argument. 766 00:42:32 --> 00:42:39 767 00:42:39 --> 00:42:41 Any other yes arguments? 768 00:42:41 --> 00:42:43 Yep? 769 00:42:43 --> 00:42:46 AUDIENCE: You could have sex with a guy with better genes, 770 00:42:46 --> 00:42:50 but remain more faithful to the guy with more resource. 771 00:42:50 --> 00:42:50 PROFESSOR: Yes, OK. 772 00:42:50 --> 00:42:53 This is a particular version of the more general argument. 773 00:42:53 --> 00:42:55 There's a resource argument here. 774 00:42:55 --> 00:42:59 He's giving a particular version, which is go have sex 775 00:42:59 --> 00:43:03 with the guy with the good genes and snooker the guy with 776 00:43:03 --> 00:43:07 the good resources and convince him that it's his kid. 777 00:43:07 --> 00:43:11 So he devotes the resources to raise his genes. 778 00:43:11 --> 00:43:19 More generally, you might just play around, just shop 779 00:43:19 --> 00:43:22 around because you get more resources in general. 780 00:43:22 --> 00:43:26 Guys will give you stuff in some fashion or other. 781 00:43:26 --> 00:43:29 So there might be sort of a quasi economic-- go out and get 782 00:43:29 --> 00:43:33 the goodies kind of bargain. 783 00:43:33 --> 00:43:35 OK, those are good yes arguments. 784 00:43:35 --> 00:43:37 How about no arguments? 785 00:43:37 --> 00:43:41 Against the notion of-- yeah? 786 00:43:41 --> 00:43:43 AUDIENCE: You could lose the resources. 787 00:43:43 --> 00:43:44 PROFESSOR: You could lose the resources. 788 00:43:44 --> 00:43:46 Why would you lose the resources? 789 00:43:46 --> 00:43:47 What's the guy's problem? 790 00:43:47 --> 00:43:49 AUDIENCE: Not his kid. 791 00:43:49 --> 00:43:51 PROFESSOR: It's not his kid. 792 00:43:51 --> 00:43:55 And this is a crucial issue. 793 00:43:55 --> 00:43:58 Again, another part of this fundamental asymmetry. 794 00:43:58 --> 00:44:02 Because it's the woman who gets pres-- president right. 795 00:44:02 --> 00:44:07 The woman who gets pregnant, she always 796 00:44:07 --> 00:44:10 knows who the mother is. 797 00:44:10 --> 00:44:11 Actually, he knows who the mother is, too. 798 00:44:11 --> 00:44:13 There's no doubt about who the mother is. 799 00:44:13 --> 00:44:18 800 00:44:18 --> 00:44:22 The maternal genes are not an issue here, paternal 801 00:44:22 --> 00:44:24 genes are an issue. 802 00:44:24 --> 00:44:27 803 00:44:27 --> 00:44:34 And doubts about paternity have a variety of consequences. 804 00:44:34 --> 00:44:39 Male sexual jealousy is a real and potentially 805 00:44:39 --> 00:44:41 dangerous phenomenon. 806 00:44:41 --> 00:44:47 In fact, I don't think there are any states where it's still 807 00:44:47 --> 00:44:52 the case-- there were states where it was the case that 808 00:44:52 --> 00:44:58 killing an unfaithful wife was not murder. 809 00:44:58 --> 00:45:00 I don't think it was ever the other way around. 810 00:45:00 --> 00:45:03 You couldn't kill your unfaithful husband, but killing 811 00:45:03 --> 00:45:09 the unfaithful wife wasn't necessarily a laudable act, but 812 00:45:09 --> 00:45:13 it wasn't murder in the way that killing somebody else was. 813 00:45:13 --> 00:45:15 I don't believe that-- anybody happen to know that they come 814 00:45:15 --> 00:45:18 from a state where you can still do that with impunity? 815 00:45:18 --> 00:45:21 816 00:45:21 --> 00:45:23 I think Louisiana was the last. 817 00:45:23 --> 00:45:28 818 00:45:28 --> 00:45:32 Oh, and there are interesting wrinkles on this. 819 00:45:32 --> 00:45:36 820 00:45:36 --> 00:45:41 When a baby is born the first question anybody asks 821 00:45:41 --> 00:45:42 is, is it a boy or girl? 822 00:45:42 --> 00:45:47 Which is an interesting factoid in its own right, but sort of 823 00:45:47 --> 00:45:49 the second topic of conversation is, who 824 00:45:49 --> 00:45:51 does the kid look like? 825 00:45:51 --> 00:45:54 And what's the answer? 826 00:45:54 --> 00:45:59 The answer is a bias towards saying that the kid 827 00:45:59 --> 00:46:02 looks like the father. 828 00:46:02 --> 00:46:05 Now why should that be the case? 829 00:46:05 --> 00:46:07 And it turns out that the bias is strong-- it depends 830 00:46:07 --> 00:46:08 who's giving the answer. 831 00:46:08 --> 00:46:12 The answer by the wife's family-- by the mother's 832 00:46:12 --> 00:46:16 family-- is more skewed towards saying it 833 00:46:16 --> 00:46:19 looks like the father. 834 00:46:19 --> 00:46:22 And there are at least two reasons why this is the case. 835 00:46:22 --> 00:46:25 One of them seems to be an effort-- again, quite 836 00:46:25 --> 00:46:29 unconscious to prove to the dad you don't have to say it looks 837 00:46:29 --> 00:46:32 like the mother, we know who the mother is. 838 00:46:32 --> 00:46:35 Saying it looks like the father is reassuring to the father who 839 00:46:35 --> 00:46:39 might otherwise deny resource to this kid or go out and kill 840 00:46:39 --> 00:46:42 the mother-- something inconvenient like that. 841 00:46:42 --> 00:46:44 So it's important to believe that this is 842 00:46:44 --> 00:46:46 your bundle of genes. 843 00:46:46 --> 00:46:50 The guy is in theoretical doubt, the woman 844 00:46:50 --> 00:46:51 is not in doubt. 845 00:46:51 --> 00:46:55 The other reason why it may be true is there is some evidence 846 00:46:55 --> 00:47:00 that babies actually look more like their fathers when they're 847 00:47:00 --> 00:47:04 young and that this wears off with age. 848 00:47:04 --> 00:47:07 If this is true it would be an interesting argument for this 849 00:47:07 --> 00:47:12 evolutionary pressure because babies who looked clearly like 850 00:47:12 --> 00:47:18 dad probably had a little edge because dad looked at this 851 00:47:18 --> 00:47:21 little bundle of joy and said, it's mine. 852 00:47:21 --> 00:47:28 And if the kid looked like the milkman or something, the kid 853 00:47:28 --> 00:47:31 may not have-- actually, can you even use that as 854 00:47:31 --> 00:47:32 an example anymore? 855 00:47:32 --> 00:47:35 Are there still milkmen out there? 856 00:47:35 --> 00:47:38 It used to be. 857 00:47:38 --> 00:47:40 It's a sort of an anachronism, like talking about 858 00:47:40 --> 00:47:44 dialing the phone. 859 00:47:44 --> 00:47:49 This is a very mid 50s kind of anachronistic sort of cliche 860 00:47:49 --> 00:47:54 about the woman who would be at home, the milkman, who would be 861 00:47:54 --> 00:47:57 the man who delivered the milk since you didn't go to the 862 00:47:57 --> 00:48:02 supermarket to buy milk-- it came to your house and then 863 00:48:02 --> 00:48:05 various other things happened and anyway. 864 00:48:05 --> 00:48:10 So much for cultural enlightenment here. 865 00:48:10 --> 00:48:17 So in any case, there's a pressure for women to be 866 00:48:17 --> 00:48:23 faithful because of basically, in some fashion because of the 867 00:48:23 --> 00:48:33 danger of alienating the male in some way or other. 868 00:48:33 --> 00:48:37 There's a problem here, sort of a problem. 869 00:48:37 --> 00:48:40 There's a potential problem with this. 870 00:48:40 --> 00:48:43 If you think about it we've just come up with a theory that 871 00:48:43 --> 00:48:47 explains why women should be faithful and shouldn't 872 00:48:47 --> 00:48:48 be faithful. 873 00:48:48 --> 00:48:53 And in fact, we could elaborate on this and say that the 874 00:48:53 --> 00:49:00 evolutionary pressures should cause-- you could argue that 875 00:49:00 --> 00:49:03 the evolutionary pressures could push women to have less 876 00:49:03 --> 00:49:06 of a sex drive therefore, making them more likely to 877 00:49:06 --> 00:49:09 remain faithful or you could have it explain that they have 878 00:49:09 --> 00:49:11 just the same sex drive, but they're supposed to 879 00:49:11 --> 00:49:12 deny the existence. 880 00:49:12 --> 00:49:14 You can have a lot of different explanations. 881 00:49:14 --> 00:49:17 882 00:49:17 --> 00:49:21 This is a problem with the theory, a theory that explains 883 00:49:21 --> 00:49:25 all possible outcomes isn't a great theory. 884 00:49:25 --> 00:49:29 On the other hand, in human mating behavior all the 885 00:49:29 --> 00:49:32 possible outcomes are out there. 886 00:49:32 --> 00:49:34 So you don't want to have a theory that just explains one 887 00:49:34 --> 00:49:37 thing because that wouldn't be an adequate theory here either. 888 00:49:37 --> 00:49:41 I think the fairer thing to say about evolutionary theory is 889 00:49:41 --> 00:49:46 that it hasn't reached a degree of sophistication where it can 890 00:49:46 --> 00:49:51 explain in detail when a woman should or should 891 00:49:51 --> 00:49:53 not be faithful. 892 00:49:53 --> 00:49:56 There are examples elsewhere of these sort of trade-off 893 00:49:56 --> 00:50:00 situations that evolutionary sorts of theories 894 00:50:00 --> 00:50:01 explain rather well. 895 00:50:01 --> 00:50:06 So an example, sort of in the same ballpark, 896 00:50:06 --> 00:50:07 comes from cuckoos. 897 00:50:07 --> 00:50:09 You know about cuckoos? 898 00:50:09 --> 00:50:11 Cuckoos are nasty birds. 899 00:50:11 --> 00:50:17 Cuckoos like to lay their eggs in somebody else's nest because 900 00:50:17 --> 00:50:20 this business of raising kids is resource intensive and 901 00:50:20 --> 00:50:24 if you can get somebody else to do it, great. 902 00:50:24 --> 00:50:28 So cuckoos lay their eggs in somebody else's nest and it 903 00:50:28 --> 00:50:36 gets better from there because the cuckoo egg hatches early 904 00:50:36 --> 00:50:40 and the cuckoo chick has this lovely reflex where what it 905 00:50:40 --> 00:50:43 does is it arches its little cuckoo back and kicks 906 00:50:43 --> 00:50:45 the other eggs out. 907 00:50:45 --> 00:50:51 So it kills off its adopted siblings and then it sits there 908 00:50:51 --> 00:50:56 making I'm hungry noises and gets fed by genetically 909 00:50:56 --> 00:50:57 unrelated birds. 910 00:50:57 --> 00:51:00 911 00:51:00 --> 00:51:03 There's an obvious problem here. 912 00:51:03 --> 00:51:06 It's in the cuckoos interest to do this, but you can't 913 00:51:06 --> 00:51:08 have too many cuckoos. 914 00:51:08 --> 00:51:12 If cuckoos do this to every nest then there's no next 915 00:51:12 --> 00:51:14 generation because there's nobody left dumb enough 916 00:51:14 --> 00:51:18 to raise your kids in the next generation. 917 00:51:18 --> 00:51:22 So there's an equilibrium, you can write down equations for 918 00:51:22 --> 00:51:28 this that say a healthy population can tolerate this 919 00:51:28 --> 00:51:31 many cuckoos; this many cheaters. 920 00:51:31 --> 00:51:36 You might ask by the way, why the stupid bird-- the stupid 921 00:51:36 --> 00:51:42 sparrow or whatever who's got a cuckoo in her nest doesn't 922 00:51:42 --> 00:51:44 say, get out of here. 923 00:51:44 --> 00:51:52 And the problem seems to be that the cuckoo behaves as a 924 00:51:52 --> 00:51:57 sort of a supernormal baby stimulus. 925 00:51:57 --> 00:52:03 You as a mommy sparrow or daddy sparrow-- you are built 926 00:52:03 --> 00:52:05 to say, oh, look at that. 927 00:52:05 --> 00:52:08 It's cute, it's a baby, I want to feed it. 928 00:52:08 --> 00:52:11 And your success is whether this thing is growing. 929 00:52:11 --> 00:52:14 And here's this honking, huge cuckoo baby. 930 00:52:14 --> 00:52:16 Wow, I hit the jackpot. 931 00:52:16 --> 00:52:18 I got the greatest baby in the world. 932 00:52:18 --> 00:52:21 Doesn't happen to be genetically related to me, 933 00:52:21 --> 00:52:23 but it's a great baby. 934 00:52:23 --> 00:52:26 And so I stuff it full of worms. 935 00:52:26 --> 00:52:29 Last year there was an article about a species of I don't 936 00:52:29 --> 00:52:32 remember what, but some other non cuckoo bird that has 937 00:52:32 --> 00:52:36 learned now how to recognize or has evolved the ability to 938 00:52:36 --> 00:52:41 recognize the cuckoos and you can't lay your cuckoo eggs in 939 00:52:41 --> 00:52:45 those nests because that species will get rid of you 940 00:52:45 --> 00:52:46 and preserve their own. 941 00:52:46 --> 00:52:49 But anyway, there's an equilibrium state here. 942 00:52:49 --> 00:52:52 You have a balance that tolerates a certain 943 00:52:52 --> 00:52:54 amount of cheating. 944 00:52:54 --> 00:53:01 The same thing happens in human relationships though the 945 00:53:01 --> 00:53:03 details are much more complicated to work out. 946 00:53:03 --> 00:53:05 But do people lie? 947 00:53:05 --> 00:53:07 AUDIENCE: Yes. 948 00:53:07 --> 00:53:08 PROFESSOR: Yeah, sure. 949 00:53:08 --> 00:53:10 Do people lie all the time? 950 00:53:10 --> 00:53:12 No, you can't do that. 951 00:53:12 --> 00:53:17 You can't have an arbitrary relationship between truth and 952 00:53:17 --> 00:53:21 udderances cannot have arbitrary truth value because 953 00:53:21 --> 00:53:23 then there wouldn't be any point to communication. 954 00:53:23 --> 00:53:29 So on average people as a whole have to tell the truth. 955 00:53:29 --> 00:53:31 Does everybody have to tell the same amount of truth? 956 00:53:31 --> 00:53:36 No, the population can tolerate some amount 957 00:53:36 --> 00:53:39 of real liars, right? 958 00:53:39 --> 00:53:43 Pathological, lying through their teeth all the time. 959 00:53:43 --> 00:53:45 Oh yes, I love you baby. 960 00:53:45 --> 00:53:47 I will devote all my resources to you. 961 00:53:47 --> 00:53:52 Liars, or whatever realm it is, but again, there's going to be 962 00:53:52 --> 00:53:56 an equilibrium equation there somewhere. 963 00:53:56 --> 00:53:59 Not as well worked out as with cuckoos that says, we can 964 00:53:59 --> 00:54:02 only tolerate so many liars. 965 00:54:02 --> 00:54:06 So you could ask the question, is there motivation for guys 966 00:54:06 --> 00:54:10 to lie in relationships? 967 00:54:10 --> 00:54:11 Are you seeing anybody else? 968 00:54:11 --> 00:54:14 Oh no, not me. 969 00:54:14 --> 00:54:20 If everybody lies about that the game falls apart. 970 00:54:20 --> 00:54:24 If some people lie about it they get away with it. 971 00:54:24 --> 00:54:27 So the population as a whole will tolerate some 972 00:54:27 --> 00:54:30 subset of cheaters. 973 00:54:30 --> 00:54:33 974 00:54:33 --> 00:54:38 One can have the hope-- the theoretical hope that another 975 00:54:38 --> 00:54:40 few generations of work in the area and you'd be able 976 00:54:40 --> 00:54:42 to write the equation. 977 00:54:42 --> 00:54:47 You'll be able to say, look, a population like an 978 00:54:47 --> 00:54:53 undergraduate population can tolerate 10% cheaters. 979 00:54:53 --> 00:54:56 If we've got 11% cheaters we have to invoke the dean's 980 00:54:56 --> 00:55:00 office or something and throw them out because the population 981 00:55:00 --> 00:55:01 will crash otherwise or something. 982 00:55:01 --> 00:55:03 Anyway, we're nowhere near that point. 983 00:55:03 --> 00:55:06 At this point we can't write the equations. 984 00:55:06 --> 00:55:08 But that seems to be the way you get to the solution 985 00:55:08 --> 00:55:11 to the problem. 986 00:55:11 --> 00:55:15 That the theory at the moment predicts kind of everything. 987 00:55:15 --> 00:55:17 The theory also doesn't predict the full range of behavior. 988 00:55:17 --> 00:55:22 I see I've got these problems listed on the handout. 989 00:55:22 --> 00:55:26 In particular, it's explaining group behavior, explaining the 990 00:55:26 --> 00:55:28 behavior of individuals is something that I'll get 991 00:55:28 --> 00:55:29 to in the next lecture. 992 00:55:29 --> 00:55:31 Actually, I'll get to some of it later in 993 00:55:31 --> 00:55:33 the present lecture. 994 00:55:33 --> 00:55:35 And the third problem, let me say a bit about that 995 00:55:35 --> 00:55:38 before we take a break. 996 00:55:38 --> 00:55:41 Is that civilization may have changed the rules. 997 00:55:41 --> 00:55:45 One of the most striking-- there's several 998 00:55:45 --> 00:55:46 examples of this. 999 00:55:46 --> 00:55:50 One of them is if you were operating in a sort of a purely 1000 00:55:50 --> 00:55:55 Darwinian kind of a world that would be very difficult 1001 00:55:55 --> 00:55:59 probably, but very different than operating in a world where 1002 00:55:59 --> 00:56:03 you are being told explicitly what is and is not 1003 00:56:03 --> 00:56:04 appropriate sexual behavior. 1004 00:56:04 --> 00:56:11 You're being told explicitly that your genes, your 1005 00:56:11 --> 00:56:13 evolutionary history if you're a male may be saying go off and 1006 00:56:13 --> 00:56:15 mate with everybody under the sun. 1007 00:56:15 --> 00:56:19 But there are societal strictures that 1008 00:56:19 --> 00:56:21 say, not really. 1009 00:56:21 --> 00:56:24 That's just not quite really right. 1010 00:56:24 --> 00:56:28 So that complicates things, but a more interesting complication 1011 00:56:28 --> 00:56:33 arises more recently in history with the advent of 1012 00:56:33 --> 00:56:36 artificial contraception. 1013 00:56:36 --> 00:56:44 If the fundamental route to these asymmetries is that women 1014 00:56:44 --> 00:56:48 get pregnant-- that sex makes you pregnant and it's only 1015 00:56:48 --> 00:56:51 women that get pregnant, what happens if you decouple 1016 00:56:51 --> 00:56:54 sex from pregnancy? 1017 00:56:54 --> 00:56:57 Does it change the game? 1018 00:56:57 --> 00:56:59 Well, potentially yes. 1019 00:56:59 --> 00:57:04 It has not made these asymmetries disappear. 1020 00:57:04 --> 00:57:07 That's a topic that I will actually return 1021 00:57:07 --> 00:57:09 to in a later lecture. 1022 00:57:09 --> 00:57:13 It's not made these asymmetries disappear and that suggests 1023 00:57:13 --> 00:57:19 that forces that shaped our brains, the evolutionary forces 1024 00:57:19 --> 00:57:24 that shaped our brains over long periods of time still 1025 00:57:24 --> 00:57:28 operate even though the rules of the game have 1026 00:57:28 --> 00:57:29 changed somewhat. 1027 00:57:29 --> 00:57:33 You can get an intuitive feeling for this-- let's 1028 00:57:33 --> 00:57:36 return to the question of female fidelity. 1029 00:57:36 --> 00:57:37 Should a woman cheat? 1030 00:57:37 --> 00:57:42 Well, part of the answer to why a female might be inclined not 1031 00:57:42 --> 00:57:46 to cheat in a relationship was that the male might be jealous 1032 00:57:46 --> 00:57:49 and that would have a variety of possible bad consequences; 1033 00:57:49 --> 00:57:53 withdrawal of resources or potentially violence in some 1034 00:57:53 --> 00:57:55 fashion, something bad might happen. 1035 00:57:55 --> 00:58:00 OK, how much do you think that those bad consequences 1036 00:58:00 --> 00:58:01 are ameliorated. 1037 00:58:01 --> 00:58:05 If when she's confronted, you know, did you cheat on me? 1038 00:58:05 --> 00:58:11 Yes, I cheated on you, but it's OK because we took precautions. 1039 00:58:11 --> 00:58:14 Do you think that makes a difference in the argument? 1040 00:58:14 --> 00:58:15 AUDIENCE: No. 1041 00:58:15 --> 00:58:19 PROFESSOR: No, intuitively it doesn't seem likely that 1042 00:58:19 --> 00:58:21 it makes a difference. 1043 00:58:21 --> 00:58:31 Suggesting that the forces that are driving these questions of 1044 00:58:31 --> 00:58:35 who should cheat and who shouldn't cheat are walled 1045 00:58:35 --> 00:58:38 off from knowledge about modern contraception. 1046 00:58:38 --> 00:58:43 In sort of the way that the forces that are driving taste 1047 00:58:43 --> 00:58:45 aversions are walled off of what you know about what 1048 00:58:45 --> 00:58:46 it is that made you sick. 1049 00:58:46 --> 00:58:49 Remember from earlier in the course, you got sick because 1050 00:58:49 --> 00:58:52 you got the flu, but you ate a tuna fish sandwich the day 1051 00:58:52 --> 00:58:55 before you got the flu and now you can't eat tuna fish anymore 1052 00:58:55 --> 00:58:58 because this little chunk of brain said, tuna fish poisoned 1053 00:58:58 --> 00:59:01 us, we never eat it again. 1054 00:59:01 --> 00:59:03 Same sort of story. 1055 00:59:03 --> 00:59:07 Somewhere in the brain is a chunk of brain that is saying-- 1056 00:59:07 --> 00:59:10 chunk of guy brain that is saying, need to know 1057 00:59:10 --> 00:59:13 woman is faithful. 1058 00:59:13 --> 00:59:13 Why? 1059 00:59:13 --> 00:59:16 Well, because I need to know whose genes they are. 1060 00:59:16 --> 00:59:17 Woman isn't pregnant. 1061 00:59:17 --> 00:59:20 I don't care. 1062 00:59:20 --> 00:59:24 I'm a very simple little chunk of brain, I just need to know 1063 00:59:24 --> 00:59:32 woman is faithful or I have unhappy things happen in me. 1064 00:59:32 --> 00:59:37 So the persistence of these sorts of asymmetries and these 1065 00:59:37 --> 00:59:41 sorts of behaviors is another argument that can be used to 1066 00:59:41 --> 00:59:47 argue that these are deep seated behaviors 1067 00:59:47 --> 00:59:48 with evolution. 1068 00:59:48 --> 00:59:53 Oh, I should say, by the way, that these are explanations 1069 00:59:53 --> 00:59:56 not excuses in any way shape or form. 1070 00:59:56 --> 01:00:01 Coming home and flipping to the other side of this right? 1071 01:00:01 --> 01:00:02 You're the guy this time. 1072 01:00:02 --> 01:00:03 Did your cheat? 1073 01:00:03 --> 01:00:06 Yes, but that's OK because I have deep seated evolutionary 1074 01:00:06 --> 01:00:10 forces within me that make it necessary for me to cheat. 1075 01:00:10 --> 01:00:12 That's an interesting explanation, but it's not an 1076 01:00:12 --> 01:00:18 excuse in a relationship any more than it's an excuse. 1077 01:00:18 --> 01:00:24 Yes, I hit my girlfriend because I was jealous. 1078 01:00:24 --> 01:00:28 You know, great, lovely, we have these great evolutionary 1079 01:00:28 --> 01:00:28 arguments for it. 1080 01:00:28 --> 01:00:30 That's not an excuse. 1081 01:00:30 --> 01:00:33 That's where you get into again, why these things are 1082 01:00:33 --> 01:00:39 politically controversial, is the possibility of turning 1083 01:00:39 --> 01:00:42 explanation into excuse. 1084 01:00:42 --> 01:00:46 You can decide well, to use an example that I will probably 1085 01:00:46 --> 01:00:52 use again, it's a little like saying, look gravity 1086 01:00:52 --> 01:00:53 is a force. 1087 01:00:53 --> 01:00:56 You can't thwart gravity, so I'm just going to 1088 01:00:56 --> 01:00:59 lie here forever. 1089 01:00:59 --> 01:01:00 Oops, lost the glasses. 1090 01:01:00 --> 01:01:01 Where'd the glasses go? 1091 01:01:01 --> 01:01:05 That's a really stupid argument and it's similarly stupid to 1092 01:01:05 --> 01:01:08 say biology is a powerful force, therefore I 1093 01:01:08 --> 01:01:11 had to do whatever. 1094 01:01:11 --> 01:01:14 There are other powerful forces out there in civilization: 1095 01:01:14 --> 01:01:17 morality, culture, whatever are powerful forces and if they say 1096 01:01:17 --> 01:01:21 don't do it, it may be hard work not to do it, but that 1097 01:01:21 --> 01:01:22 doesn't mean you shouldn't do it. 1098 01:01:22 --> 01:01:25 Or you should do-- whatever, you got the basic idea. 1099 01:01:25 --> 01:01:28 Well on that sentence with way too many double negatives in 1100 01:01:28 --> 01:01:33 it, let us take a brief break and then I'll turn 1101 01:01:33 --> 01:01:35 to the question of individual behavior. 1102 01:01:35 --> 01:01:38 1103 01:01:38 --> 01:02:11 [INTERPOSING VOICES] 1104 01:02:11 --> 01:02:12 PROFESSOR: Oh, thank you. 1105 01:02:12 --> 01:02:37 1106 01:02:37 --> 01:02:39 AUDIENCE: Should we do it before-- I mean, after they 1107 01:02:39 --> 01:02:40 come back from the break maybe? 1108 01:02:40 --> 01:02:43 Or would you prefer at the end? 1109 01:02:43 --> 01:02:45 1110 01:02:45 --> 01:02:46 PROFESSOR: We [UNINTELLIGIBLE] 1111 01:02:46 --> 01:02:48 AUDIENCE: Basically what it is we're doing the comedy passes, 1112 01:02:48 --> 01:02:50 whoever wants one we just have to pass them out. 1113 01:02:50 --> 01:02:53 PROFESSOR: Oh no, if you're going to pass stuff out, 1114 01:02:53 --> 01:02:54 be here at the end. 1115 01:02:54 --> 01:02:57 [INTERPOSING VOICES] 1116 01:02:57 --> 01:03:02 PROFESSOR: Yep, I'll do my best. 1117 01:03:02 --> 01:03:03 Will it be funny? 1118 01:03:03 --> 01:03:05 1119 01:03:05 --> 01:03:08 Quick, funny announcement. 1120 01:03:08 --> 01:03:10 All right, so be here in about 20 minutes. 1121 01:03:10 --> 01:03:12 AUDIENCE: Yeah, no problem. 1122 01:03:12 --> 01:03:15 1123 01:03:15 --> 01:03:18 PROFESSOR: So, let me elaborate. 1124 01:03:18 --> 01:03:20 I realized looking at the handout that I didn't elaborate 1125 01:03:20 --> 01:03:26 particularly well on this problem 2 part about these 1126 01:03:26 --> 01:03:30 evolutionary theories not explaining the full 1127 01:03:30 --> 01:03:33 range of behavior well. 1128 01:03:33 --> 01:03:41 So it explains perhaps-- the theory as elaborated thus far 1129 01:03:41 --> 01:03:45 explains for instance, why you might be attracted to one 1130 01:03:45 --> 01:03:47 person or another, but it doesn't explain what you 1131 01:03:47 --> 01:03:50 do in any particular way. 1132 01:03:50 --> 01:03:56 So you see an attractive, potential mate, if you're birds 1133 01:03:56 --> 01:03:58 you might do some sort of weird mating dance or 1134 01:03:58 --> 01:04:00 something like that. 1135 01:04:00 --> 01:04:03 If you're a human you might do some weird mating dance 1136 01:04:03 --> 01:04:05 or something like that. 1137 01:04:05 --> 01:04:09 You can ask yourself about what do you do if there's an 1138 01:04:09 --> 01:04:12 attractive mate possibility? 1139 01:04:12 --> 01:04:17 You could dance, you could hang around, you could act pathetic, 1140 01:04:17 --> 01:04:20 you could act non-pathetic. 1141 01:04:20 --> 01:04:25 You could get person A to talk to person B and who knows C, 1142 01:04:25 --> 01:04:28 who's the uncle of D or something like that. 1143 01:04:28 --> 01:04:31 1144 01:04:31 --> 01:04:33 Just knowing that there was evolutionary pressure here 1145 01:04:33 --> 01:04:37 isn't really a full story about human mating behavior by any 1146 01:04:37 --> 01:04:39 stretch of the imagination. 1147 01:04:39 --> 01:04:43 What's going to elaborate on it, you can probably get a good 1148 01:04:43 --> 01:04:47 piece of mileage from asking about law of effect 1149 01:04:47 --> 01:04:49 kinds of things. 1150 01:04:49 --> 01:04:53 What you do in mating situations or courtship 1151 01:04:53 --> 01:04:57 situations is going to be shaped, at least in part, by 1152 01:04:57 --> 01:05:01 the schedule of reinforcement. 1153 01:05:01 --> 01:05:08 You do a mating dance and the potential mate responds, you're 1154 01:05:08 --> 01:05:10 going to be inclined to do that dance more-- it's not 1155 01:05:10 --> 01:05:11 why birds do it. 1156 01:05:11 --> 01:05:14 Birds are wired typically to do the dance, but if you go off 1157 01:05:14 --> 01:05:19 and do some weird dance and he or she says, hey, this is good. 1158 01:05:19 --> 01:05:20 You'll do it again. 1159 01:05:20 --> 01:05:25 1160 01:05:25 --> 01:05:27 The whole ritual, I don't know what you want to call-- who 1161 01:05:27 --> 01:05:32 touches who when, where, and how is also heavily shaped by 1162 01:05:32 --> 01:05:35 law of effect sorts of things. 1163 01:05:35 --> 01:05:38 If it's rewarded it happens again. 1164 01:05:38 --> 01:05:41 If it's not rewarded it doesn't happen again. 1165 01:05:41 --> 01:05:45 More on this later, but I did want to just say that there's 1166 01:05:45 --> 01:05:48 nothing in these sort of evolutionary psych theory 1167 01:05:48 --> 01:05:52 that really talks to that. 1168 01:05:52 --> 01:06:05 Now let me go onto try to say what does talk about individual 1169 01:06:05 --> 01:06:10 behavior in romantic relationships. 1170 01:06:10 --> 01:06:16 You know, to get beyond this notion of what average 1171 01:06:16 --> 01:06:20 populations do in a world full of potential mates, why are you 1172 01:06:20 --> 01:06:24 attracted to this one now? 1173 01:06:24 --> 01:06:28 What can we say about that? 1174 01:06:28 --> 01:06:30 There certainly seems to be something to explain. 1175 01:06:30 --> 01:06:31 There are a variety of candidate sorts of 1176 01:06:31 --> 01:06:33 theories out there. 1177 01:06:33 --> 01:06:39 One of them is nicely encapsulated in shakes-- oh I 1178 01:06:39 --> 01:06:44 realized I didn't put the most clear cut piece of citation on 1179 01:06:44 --> 01:06:46 that quote at the bottom of page 3-- That's Midsummer 1180 01:06:46 --> 01:06:47 Night's Dream. 1181 01:06:47 --> 01:06:51 Shakespeare's Midsummer Night's Dream and Shakespeare has 1182 01:06:51 --> 01:06:55 Theseus, Duke of Athens say, that lovers and madmen have 1183 01:06:55 --> 01:07:00 such seething brains, such shaping fantasies that 1184 01:07:00 --> 01:07:03 apprehend more than cool reason ever comprehends. 1185 01:07:03 --> 01:07:06 The lunatic, the lover, and the poet are of 1186 01:07:06 --> 01:07:08 imagination all compact. 1187 01:07:08 --> 01:07:12 This is a theory of romantic behavior that says you're 1188 01:07:12 --> 01:07:15 attracted to whom you're attracted to at the moment and 1189 01:07:15 --> 01:07:19 you're doing what you're doing in response to that now 1190 01:07:19 --> 01:07:21 because you're nuts. 1191 01:07:21 --> 01:07:27 I mean, basically it's a form of insanity, and not uncommon 1192 01:07:27 --> 01:07:31 theory that shows up in literary circles. 1193 01:07:31 --> 01:07:33 1194 01:07:33 --> 01:07:38 The place to get some intuitive feeling for that is to remember 1195 01:07:38 --> 01:07:42 what it felt like if you were ever completely infatuated 1196 01:07:42 --> 01:07:44 with somebody. 1197 01:07:44 --> 01:07:46 Preferably somebody who didn't know you were 1198 01:07:46 --> 01:07:49 infatuated with them. 1199 01:07:49 --> 01:07:55 Some random other person across the crowded room kind of thing. 1200 01:07:55 --> 01:07:59 That has the feeling of being more or less, out of your mind. 1201 01:07:59 --> 01:08:05 But you don't realize at the time and reams of bad high 1202 01:08:05 --> 01:08:09 school poetry are written unders those conditions. 1203 01:08:09 --> 01:08:13 And if you're very lucky nobody else gets to see 1204 01:08:13 --> 01:08:15 that stuff, mostly. 1205 01:08:15 --> 01:08:18 1206 01:08:18 --> 01:08:21 In my experience, back when I was in high school-- how many 1207 01:08:21 --> 01:08:23 people have ever seen a book called Jonathan 1208 01:08:23 --> 01:08:25 Livingston Seagull? 1209 01:08:25 --> 01:08:27 Oh, it's still out there. 1210 01:08:27 --> 01:08:29 It's very sappy. 1211 01:08:29 --> 01:08:33 And it was this sort of thing you gave to somebody who you 1212 01:08:33 --> 01:08:38 were deeply in love with, preferably in high school. 1213 01:08:38 --> 01:08:43 And it turns out that both my wife and I have copies of this 1214 01:08:43 --> 01:08:48 book given to us by people other than each other because 1215 01:08:48 --> 01:08:50 we didn't know each other in high school-- both with 1216 01:08:50 --> 01:08:58 inscriptions so florid that you just can't read them. 1217 01:08:58 --> 01:09:00 One of these I mean, why haven't we destroyed them? 1218 01:09:00 --> 01:09:03 Well, there's a certain nostalgia there of some sort 1219 01:09:03 --> 01:09:06 and you gotta save these things for your children. 1220 01:09:06 --> 01:09:12 One day one of my kids is going to be up in the attic and find 1221 01:09:12 --> 01:09:19 this thing and read it and fall down dead laughing. 1222 01:09:19 --> 01:09:24 All right, the relevant question here is that's not a 1223 01:09:24 --> 01:09:30 bad theory, why isn't this the abnormal psych part 1224 01:09:30 --> 01:09:31 of the course? 1225 01:09:31 --> 01:09:34 Why aren't we talking about love in the context 1226 01:09:34 --> 01:09:35 of psychopathology? 1227 01:09:35 --> 01:09:38 1228 01:09:38 --> 01:09:41 What's the answer? 1229 01:09:41 --> 01:09:43 Nobody knows what the answer is. 1230 01:09:43 --> 01:09:43 Yep? 1231 01:09:43 --> 01:09:45 AUDIENCE: Psychopathology generally deals with things 1232 01:09:45 --> 01:09:48 that are [UNINTELLIGIBLE] 1233 01:09:48 --> 01:09:51 PROFESSOR: Yeah, there's a reason it's called abnormal 1234 01:09:51 --> 01:09:53 psychology as a [UNINTELLIGIBLE]. 1235 01:09:53 --> 01:09:58 Now look, I don't know quite what would happen if bad people 1236 01:09:58 --> 01:10:02 found a way to put something in the water that made us 1237 01:10:02 --> 01:10:04 floridly schizophrenic. 1238 01:10:04 --> 01:10:08 If it became the majority state it would still be 1239 01:10:08 --> 01:10:11 psychopathological probably, but by and large what we talk 1240 01:10:11 --> 01:10:18 about in abnormal psychology is abnormal and being in love may 1241 01:10:18 --> 01:10:20 be a sort of insanity, but it's a very-- well look, 1242 01:10:20 --> 01:10:22 Shakespeare knew this too. 1243 01:10:22 --> 01:10:25 So if we borrow from As You Like It, we have the 1244 01:10:25 --> 01:10:33 explanation of this given in this case by Rosalind in As You 1245 01:10:33 --> 01:10:36 Like It saying that love is merely madness, merely a 1246 01:10:36 --> 01:10:39 madness and I tell you, deserves a dark house and 1247 01:10:39 --> 01:10:41 a whip as madman do. 1248 01:10:41 --> 01:10:45 Which tells you something about Elizabethan psychotherapy. 1249 01:10:45 --> 01:10:49 The reason they are not so punished and cured, which also 1250 01:10:49 --> 01:10:52 tells you something about Elizabethan psychotherapy; the 1251 01:10:52 --> 01:10:55 notion was not that you were just being nasty to crazy 1252 01:10:55 --> 01:10:58 people, but that being nasty was curative. 1253 01:10:58 --> 01:11:01 The reason they are not so punished and cured is that the 1254 01:11:01 --> 01:11:06 lunacy is so ordinary that the whippers are in love too. 1255 01:11:06 --> 01:11:10 It doesn't make any real sense, it's not a useful theory to say 1256 01:11:10 --> 01:11:14 that being in love is a form of insanity because it's 1257 01:11:14 --> 01:11:17 essentially a universal form of insanity. 1258 01:11:17 --> 01:11:23 You might think that there's nothing much to say in an intro 1259 01:11:23 --> 01:11:26 psych class about this at all and that the whole topic is 1260 01:11:26 --> 01:11:30 kind of best left to Shakespeare and other 1261 01:11:30 --> 01:11:31 literary sources. 1262 01:11:31 --> 01:11:35 That's actually not a bad argument, but I think there is 1263 01:11:35 --> 01:11:41 something useful to be said in the context of psychology. 1264 01:11:41 --> 01:11:44 We can switch back to Shakespeare and ask-- wait, 1265 01:11:44 --> 01:11:46 first we have to check on how high school education 1266 01:11:46 --> 01:11:47 is going these days. 1267 01:11:47 --> 01:11:49 How many people have to read Romeo and Juliet in 1268 01:11:49 --> 01:11:50 high school somewhere? 1269 01:11:50 --> 01:11:51 OK, good. 1270 01:11:51 --> 01:11:52 Just checking. 1271 01:11:52 --> 01:11:55 1272 01:11:55 --> 01:12:01 Romeo is looking across a crowded dancehall here and he 1273 01:12:01 --> 01:12:07 sees Juliet and he's supposed to be in love with? 1274 01:12:07 --> 01:12:08 AUDIENCE: Rosaline. 1275 01:12:08 --> 01:12:09 PROFESSOR: Rosaline. 1276 01:12:09 --> 01:12:12 Good, you got that question right on the test. 1277 01:12:12 --> 01:12:14 He's been mooning around about this woman Rosaline. 1278 01:12:14 --> 01:12:18 He walks in, he sees Juliet and it's oh, she doth make the 1279 01:12:18 --> 01:12:20 [UNINTELLIGIBLE PHRASE]. 1280 01:12:20 --> 01:12:23 You can see why I'm not a Shakespearian actor. 1281 01:12:23 --> 01:12:27 She doth teach the torches to burn bright and 1282 01:12:27 --> 01:12:28 all that good stuff. 1283 01:12:28 --> 01:12:32 1284 01:12:32 --> 01:12:33 Why? 1285 01:12:33 --> 01:12:35 What can you say about it? 1286 01:12:35 --> 01:12:36 There are a variety of things. 1287 01:12:36 --> 01:12:38 Well, we can develop what we can call the chemical 1288 01:12:38 --> 01:12:39 theory of love here. 1289 01:12:39 --> 01:12:42 We passed through the insanity theory, let's work on the 1290 01:12:42 --> 01:12:45 chemical theory a little bit. 1291 01:12:45 --> 01:12:48 Chemical theory gets you a certain distance. 1292 01:12:48 --> 01:12:49 Oh, I didn't put this on the handout yet because 1293 01:12:49 --> 01:12:53 I wasn't convinced I was going to get here. 1294 01:12:53 --> 01:12:55 I'll put a few of these terms on there next time, but 1295 01:12:55 --> 01:12:57 you could write on the back of the handout. 1296 01:12:57 --> 01:13:02 So chemical aspects. 1297 01:13:02 --> 01:13:06 One thing that's related to chemical aspects is 1298 01:13:06 --> 01:13:08 the proximity factor. 1299 01:13:08 --> 01:13:15 You want to get two things to interact and make heat, you 1300 01:13:15 --> 01:13:17 gotta bring them together. 1301 01:13:17 --> 01:13:25 It sounds trivial, but the scary version of this is that 1302 01:13:25 --> 01:13:30 a not insignificant number of you will meet your 1303 01:13:30 --> 01:13:32 eventual mate here. 1304 01:13:32 --> 01:13:36 Not here like in 10-250 right now, but during your 1305 01:13:36 --> 01:13:40 undergraduate years at MIT. 1306 01:13:40 --> 01:13:45 So you know, somebody in this room may be that person 1307 01:13:45 --> 01:13:46 or something like that. 1308 01:13:46 --> 01:13:49 One of the reasons is it's a great deal easier to fall 1309 01:13:49 --> 01:13:53 in love with somebody you actually interact with. 1310 01:13:53 --> 01:14:04 There are lovely people at Cal Tech I'm told, but mostly-- no? 1311 01:14:04 --> 01:14:08 Well, there are bitter, jealous, disappointed people 1312 01:14:08 --> 01:14:09 at Cal Tech I'm told. 1313 01:14:09 --> 01:14:14 All of whom actually wanted to go to MIT, but anyway, 1314 01:14:14 --> 01:14:17 you see the point. 1315 01:14:17 --> 01:14:18 So proximity helps. 1316 01:14:18 --> 01:14:26 Now another chemical aspect of this romantic love business is 1317 01:14:26 --> 01:14:30 that if you want a chemical reaction to speed up one of 1318 01:14:30 --> 01:14:33 the things that's useful to do is to add heat, right? 1319 01:14:33 --> 01:14:36 1320 01:14:36 --> 01:14:38 That works, too. 1321 01:14:38 --> 01:14:45 And it works in not just like turning up the thermostat, but 1322 01:14:45 --> 01:14:52 you are more likely to fall in love with somebody if your 1323 01:14:52 --> 01:14:55 arousal level is up. 1324 01:14:55 --> 01:14:57 That seems pretty obvious. 1325 01:14:57 --> 01:15:02 The non-obvious piece of it is that you're pretty stupid about 1326 01:15:02 --> 01:15:05 this and you don't care too much where the 1327 01:15:05 --> 01:15:06 arousal comes from. 1328 01:15:06 --> 01:15:10 The Romeo and Juliet thing is not a bad example. 1329 01:15:10 --> 01:15:14 Romeo is which family? 1330 01:15:14 --> 01:15:15 AUDIENCE: Montague. 1331 01:15:15 --> 01:15:16 PROFESSOR: Montague. 1332 01:15:16 --> 01:15:17 That sounds right. 1333 01:15:17 --> 01:15:22 OK, Romeo is at who's party? 1334 01:15:22 --> 01:15:22 AUDIENCE: [UNINTELLIGIBLE] 1335 01:15:22 --> 01:15:25 PROFESSOR: Do they want him at this party? 1336 01:15:25 --> 01:15:27 What are they going to do if they find him? 1337 01:15:27 --> 01:15:27 AUDIENCE: Kill him. 1338 01:15:27 --> 01:15:30 PROFESSOR: So how does that make him feel? 1339 01:15:30 --> 01:15:31 AUDIENCE: Aroused. 1340 01:15:31 --> 01:15:35 1341 01:15:35 --> 01:15:41 PROFESSOR: His little heart is going pitter pat, right? 1342 01:15:41 --> 01:15:49 There is some sense in which that contributes to-- that 1343 01:15:49 --> 01:15:52 modulates how attractive you think somebody else is. 1344 01:15:52 --> 01:15:57 1345 01:15:57 --> 01:16:00 The clearest pop culture example of this is ask 1346 01:16:00 --> 01:16:06 yourself about the standard adventure movie paradigm. 1347 01:16:06 --> 01:16:08 It's got a guy, it's got a girl, right? 1348 01:16:08 --> 01:16:11 Do they like each other at the beginning of the movie? 1349 01:16:11 --> 01:16:12 AUDIENCE: No. 1350 01:16:12 --> 01:16:14 PROFESSOR: What do they do for the duration of the movie? 1351 01:16:14 --> 01:16:17 They find themselves in disasterous situations after 1352 01:16:17 --> 01:16:19 disasterous situation. 1353 01:16:19 --> 01:16:20 Do they like each other during? 1354 01:16:20 --> 01:16:24 No, no, they spend the whole movie sniping each other and 1355 01:16:24 --> 01:16:26 double crosssing each other and stuff like that. 1356 01:16:26 --> 01:16:29 The end of the movie they're both hanging by one fingernail 1357 01:16:29 --> 01:16:33 from the helicopter over the volcano or something like that 1358 01:16:33 --> 01:16:35 and what do they realize? 1359 01:16:35 --> 01:16:37 We're in love. 1360 01:16:37 --> 01:16:38 This is great. 1361 01:16:38 --> 01:16:41 1362 01:16:41 --> 01:16:44 It sounds silly, but the fact that we have been willing to 1363 01:16:44 --> 01:16:48 tolerate that plot line forever suggests that 1364 01:16:48 --> 01:16:51 there's something to it. 1365 01:16:51 --> 01:16:54 OK, I got enough time to tell you about what is arguably one 1366 01:16:54 --> 01:16:58 of the great experiments in experimental psychology. 1367 01:16:58 --> 01:17:00 Did I already tell you about the shaky bridge experiment? 1368 01:17:00 --> 01:17:00 AUDIENCE: No. 1369 01:17:00 --> 01:17:03 PROFESSOR: No, good. 1370 01:17:03 --> 01:17:07 This is an experiment so good that I did a pilgrimage to the 1371 01:17:07 --> 01:17:12 place where it was done, which turns out to be in Vancouver. 1372 01:17:12 --> 01:17:17 Vancouver has a park with a deep gorge and a Raiders of 1373 01:17:17 --> 01:17:21 the Lost Ark style suspension bridge going across it. 1374 01:17:21 --> 01:17:25 Or Shrek, you know with the donkey going across-- 1375 01:17:25 --> 01:17:26 you know the bridge. 1376 01:17:26 --> 01:17:28 No volcanoes or dragons and anything, but 1377 01:17:28 --> 01:17:30 it's a shaky bridge. 1378 01:17:30 --> 01:17:32 Here's what they did. 1379 01:17:32 --> 01:17:34 You're a guy for this experiment. 1380 01:17:34 --> 01:17:40 You're a guy and you are walking across this shaky 1381 01:17:40 --> 01:17:46 bridge and in the middle of the bridge you meet a woman. 1382 01:17:46 --> 01:17:51 And she says, I'm doing a study for psychology, would you fill 1383 01:17:51 --> 01:17:54 out my little questionnaire? 1384 01:17:54 --> 01:17:57 Well, OK. 1385 01:17:57 --> 01:17:59 As part of process says, there's [UNINTELLIGIBLE] 1386 01:17:59 --> 01:18:03 if you want to know more about this experiment once we've 1387 01:18:03 --> 01:18:07 collected the data, you can phone me at this 1388 01:18:07 --> 01:18:08 number at the lab. 1389 01:18:08 --> 01:18:11 My name is Sarah. 1390 01:18:11 --> 01:18:14 OK, so that's group 1. 1391 01:18:14 --> 01:18:17 Group 2 turns out round the corner from this shaky bridge, 1392 01:18:17 --> 01:18:19 there's another bridge over the same river, it's a 1393 01:18:19 --> 01:18:21 big concrete slab. 1394 01:18:21 --> 01:18:23 It don't shake at all. 1395 01:18:23 --> 01:18:25 You're a different white guy. 1396 01:18:25 --> 01:18:26 White guy? 1397 01:18:26 --> 01:18:27 I don't remember if you're a white guy. 1398 01:18:27 --> 01:18:28 You're a guy. 1399 01:18:28 --> 01:18:32 You're walking across the bridge and you meet a 1400 01:18:32 --> 01:18:35 woman and same story. 1401 01:18:35 --> 01:18:39 If you're interested in the results of this experiment 1402 01:18:39 --> 01:18:42 phone this number and ask for Rebecca. 1403 01:18:42 --> 01:18:47 Needless to say, Rebecca and Sarah are the same person. 1404 01:18:47 --> 01:18:51 The only thing that differs is whether you met her on the 1405 01:18:51 --> 01:18:54 shaky bridge on the nonshaky bridge. 1406 01:18:54 --> 01:18:58 That data are, who calls? 1407 01:18:58 --> 01:19:02 So your call up the number, some guy answers, you 1408 01:19:02 --> 01:19:05 say is Rebecca there? 1409 01:19:05 --> 01:19:09 And he says, no, no I'll take a message and hangs up the phone. 1410 01:19:09 --> 01:19:12 Another one for Rebecca. 1411 01:19:12 --> 01:19:18 It turns out that more guys who met Sarah on the shaky bridge 1412 01:19:18 --> 01:19:22 phone in than who met Rebecca on the solid bridge. 1413 01:19:22 --> 01:19:24 Why is that? 1414 01:19:24 --> 01:19:29 The argument-- this arousal heat argument is, it's 1415 01:19:29 --> 01:19:32 known in the trade as misattribution of arousal. 1416 01:19:32 --> 01:19:38 You walk across the bridge, you meet a woman person, you ask 1417 01:19:38 --> 01:19:41 yourself, how do I feel? 1418 01:19:41 --> 01:19:43 My heart is beating. 1419 01:19:43 --> 01:19:45 My palms are sweaty. 1420 01:19:45 --> 01:19:47 It must be love. 1421 01:19:47 --> 01:19:49 1422 01:19:49 --> 01:19:52 And it's enough of an effect to change whether or not you'll 1423 01:19:52 --> 01:19:57 phone up to get the results of the experiment. 1424 01:19:57 --> 01:20:01 Look, you shouldn't overstress the result. 1425 01:20:01 --> 01:20:03 Nobody's done this particular experiment, but if you meet a 1426 01:20:03 --> 01:20:07 chicken in the middle of the bridge you don't say, 1427 01:20:07 --> 01:20:08 my heart is beating. 1428 01:20:08 --> 01:20:09 My palm's are sweaty. 1429 01:20:09 --> 01:20:12 I love the chicken. 1430 01:20:12 --> 01:20:14 But it does modulate things. 1431 01:20:14 --> 01:20:15