WEBVTT 00:00:00.000 --> 00:00:02.520 align:middle line:84% The following content is provided under a Creative 00:00:02.520 --> 00:00:04.030 align:middle line:90% Commons license. 00:00:04.030 --> 00:00:06.370 align:middle line:84% Your support will help MIT OpenCourseWare 00:00:06.370 --> 00:00:10.740 align:middle line:84% continue to offer high quality educational resources for free. 00:00:10.740 --> 00:00:13.350 align:middle line:84% To make a donation or view additional materials 00:00:13.350 --> 00:00:17.237 align:middle line:84% from hundreds of MIT courses, visit MIT OpenCourseWare 00:00:17.237 --> 00:00:17.862 align:middle line:90% at ocw.mit.edu. 00:00:17.862 --> 00:00:22.523 align:middle line:90% 00:00:22.523 --> 00:00:24.940 align:middle line:84% PROFESSOR: Maybe a few of you were expecting a quiz today. 00:00:24.940 --> 00:00:27.643 align:middle line:84% But I actually said in class on Friday 00:00:27.643 --> 00:00:29.310 align:middle line:84% that I wouldn't give the quiz this week. 00:00:29.310 --> 00:00:32.870 align:middle line:90% 00:00:32.870 --> 00:00:37.970 align:middle line:84% So sticking with that, I'm not giving it. 00:00:37.970 --> 00:00:42.140 align:middle line:84% It was to be on the Wilson notes. 00:00:42.140 --> 00:00:44.190 align:middle line:84% Well, if we can fit it in later, we might. 00:00:44.190 --> 00:00:49.220 align:middle line:84% But I want you to focus on your projects, 00:00:49.220 --> 00:00:53.610 align:middle line:84% because the reading is not very heavy this week. 00:00:53.610 --> 00:00:58.260 align:middle line:84% First is his chapter on cultural determinism. 00:00:58.260 --> 00:01:02.130 align:middle line:84% So we'll talk about that today, and then 00:01:02.130 --> 00:01:07.410 align:middle line:84% the remaining matters on Friday and Monday. 00:01:07.410 --> 00:01:10.190 align:middle line:90% 00:01:10.190 --> 00:01:12.480 align:middle line:90% Sorry, that left projector-- 00:01:12.480 --> 00:01:16.980 align:middle line:84% the bulb won't come on, at least not from here. 00:01:16.980 --> 00:01:22.570 align:middle line:90% 00:01:22.570 --> 00:01:28.720 align:middle line:84% This is how Alcock starts this chapter 00:01:28.720 --> 00:01:30.410 align:middle line:90% on cultural determinism. 00:01:30.410 --> 00:01:35.350 align:middle line:90% He quotes this sociology book. 00:01:35.350 --> 00:01:40.780 align:middle line:84% "Human biology does nothing to structure human society." 00:01:40.780 --> 00:01:46.370 align:middle line:84% And that's common belief among sociologists 00:01:46.370 --> 00:01:50.530 align:middle line:84% and cultural anthropologist, as we shall see. 00:01:50.530 --> 00:01:54.340 align:middle line:90% They don't like sociobiology. 00:01:54.340 --> 00:01:57.810 align:middle line:90% And some of that is still true. 00:01:57.810 --> 00:02:02.930 align:middle line:84% The arguments, I think, are more against biology 00:02:02.930 --> 00:02:06.060 align:middle line:84% in general, when it concerns evolution 00:02:06.060 --> 00:02:07.475 align:middle line:90% applied to human beings. 00:02:07.475 --> 00:02:10.259 align:middle line:90% 00:02:10.259 --> 00:02:15.720 align:middle line:84% Dennett in '95 called it "Darwin's dangerous idea." 00:02:15.720 --> 00:02:23.690 align:middle line:84% [CHUCKLING] It's not just due to interpretations 00:02:23.690 --> 00:02:26.360 align:middle line:84% that are common among followers of religions. 00:02:26.360 --> 00:02:34.390 align:middle line:84% It's also found in academia, in these groups I mentioned, 00:02:34.390 --> 00:02:37.210 align:middle line:90% and educators as well. 00:02:37.210 --> 00:02:39.050 align:middle line:84% But there are certain errors that are 00:02:39.050 --> 00:02:40.710 align:middle line:90% repeated in their statements. 00:02:40.710 --> 00:02:44.780 align:middle line:84% And one is, you could say, the Arab false dichotomy. 00:02:44.780 --> 00:02:47.450 align:middle line:90% 00:02:47.450 --> 00:02:48.570 align:middle line:90% So what is the dichotomy? 00:02:48.570 --> 00:02:51.540 align:middle line:90% 00:02:51.540 --> 00:02:54.820 align:middle line:84% They're saying they favor one side, not the other side. 00:02:54.820 --> 00:02:59.390 align:middle line:90% It's either culture or biology. 00:02:59.390 --> 00:03:01.250 align:middle line:90% Either learned or innate. 00:03:01.250 --> 00:03:03.100 align:middle line:90% Either nature or nurture. 00:03:03.100 --> 00:03:05.550 align:middle line:90% We've talked about this before. 00:03:05.550 --> 00:03:08.170 align:middle line:90% It's actually always both. 00:03:08.170 --> 00:03:13.770 align:middle line:84% The same is true for culture, evolutionary influences, 00:03:13.770 --> 00:03:17.560 align:middle line:84% and cultural influences on human behavior. 00:03:17.560 --> 00:03:21.980 align:middle line:84% It's just a nature-nurture issue. 00:03:21.980 --> 00:03:28.640 align:middle line:84% They also confuse proximate and evolutionary or ultimate 00:03:28.640 --> 00:03:30.500 align:middle line:90% hypotheses. 00:03:30.500 --> 00:03:32.605 align:middle line:84% That's also very common in their statements. 00:03:32.605 --> 00:03:37.670 align:middle line:90% 00:03:37.670 --> 00:03:42.660 align:middle line:84% Alcock tells the story of Frank Boas and his students. 00:03:42.660 --> 00:03:46.590 align:middle line:90% Boas was very well known. 00:03:46.590 --> 00:03:50.380 align:middle line:84% He calls him the first modern cultural anthropologist 00:03:50.380 --> 00:03:53.000 align:middle line:90% of note. 00:03:53.000 --> 00:03:58.920 align:middle line:84% And he asserted his belief in the autonomy of culture 00:03:58.920 --> 00:04:03.690 align:middle line:84% from biology, thereby, according to Alcock, 00:04:03.690 --> 00:04:05.560 align:middle line:84% freeing the study of human behavior 00:04:05.560 --> 00:04:10.450 align:middle line:84% from evolutionary biology, which had become admittedly 00:04:10.450 --> 00:04:16.149 align:middle line:84% tainted by many people who associated it with racism, 00:04:16.149 --> 00:04:18.480 align:middle line:90% social Darwinism, and eugenics. 00:04:18.480 --> 00:04:22.200 align:middle line:90% 00:04:22.200 --> 00:04:26.330 align:middle line:84% They were, as you know from reading earlier in the book, 00:04:26.330 --> 00:04:28.660 align:middle line:90% used by critics of sociobiology. 00:04:28.660 --> 00:04:33.110 align:middle line:90% 00:04:33.110 --> 00:04:41.290 align:middle line:84% So Boas, at least according to his students, 00:04:41.290 --> 00:04:44.070 align:middle line:84% promoted this idea that the cultural practices 00:04:44.070 --> 00:04:48.430 align:middle line:84% are limitless and essentially arbitrary in nature. 00:04:48.430 --> 00:04:51.150 align:middle line:84% And one of those students became very well known-- 00:04:51.150 --> 00:04:52.630 align:middle line:90% Margaret Mead. 00:04:52.630 --> 00:04:56.450 align:middle line:84% I remember meeting a friend of mine in high school-- 00:04:56.450 --> 00:04:59.830 align:middle line:84% a girl who had mapped out her career 00:04:59.830 --> 00:05:01.700 align:middle line:84% based on the career of Margaret Mead. 00:05:01.700 --> 00:05:04.270 align:middle line:84% She was going to become a cultural anthropologist. 00:05:04.270 --> 00:05:06.890 align:middle line:84% She was going to travel, give lectures, get paid for them, 00:05:06.890 --> 00:05:08.932 align:middle line:84% and so on and so forth-- just like Margaret Mead. 00:05:08.932 --> 00:05:13.030 align:middle line:90% 00:05:13.030 --> 00:05:15.375 align:middle line:84% I don't know how that turned out. 00:05:15.375 --> 00:05:16.770 align:middle line:90% [LAUGHTER] 00:05:16.770 --> 00:05:21.800 align:middle line:90% Anyway, this was the book. 00:05:21.800 --> 00:05:23.920 align:middle line:84% Margaret Mead wrote this book entitled, 00:05:23.920 --> 00:05:26.110 align:middle line:90% Coming of Age in Samoa. 00:05:26.110 --> 00:05:30.190 align:middle line:84% It was written '28, or published in '28. 00:05:30.190 --> 00:05:32.790 align:middle line:90% It was very widely quoted. 00:05:32.790 --> 00:05:35.940 align:middle line:84% It certainly was well known up to about 1975. 00:05:35.940 --> 00:05:39.710 align:middle line:84% And I think it's declined somewhat since then. 00:05:39.710 --> 00:05:41.990 align:middle line:84% And there are good reasons for that. 00:05:41.990 --> 00:05:47.350 align:middle line:84% So let's look at why would people be interested in Samoa? 00:05:47.350 --> 00:05:49.420 align:middle line:84% Because she claimed that the society 00:05:49.420 --> 00:05:54.210 align:middle line:84% there was very different from American society. 00:05:54.210 --> 00:06:00.770 align:middle line:84% She said they were sexually free. 00:06:00.770 --> 00:06:03.500 align:middle line:84% There was no conflict between kids and parents. 00:06:03.500 --> 00:06:05.400 align:middle line:84% They were allowed to do whatever they wanted. 00:06:05.400 --> 00:06:09.040 align:middle line:84% There was no rape, and so on so forth. 00:06:09.040 --> 00:06:11.460 align:middle line:90% One of these idyllic societies. 00:06:11.460 --> 00:06:14.040 align:middle line:90% 00:06:14.040 --> 00:06:23.930 align:middle line:84% Well, she was only there for 12 weeks, 00:06:23.930 --> 00:06:27.600 align:middle line:84% and interviewed a group of young women there. 00:06:27.600 --> 00:06:31.150 align:middle line:84% She quickly learned enough of the language. 00:06:31.150 --> 00:06:34.810 align:middle line:84% She could communicate with them, but that was 00:06:34.810 --> 00:06:36.800 align:middle line:90% the extent of her actual study. 00:06:36.800 --> 00:06:41.520 align:middle line:84% Well, Derek Freeman went there much later. 00:06:41.520 --> 00:06:43.830 align:middle line:90% And it led to a book in 1983. 00:06:43.830 --> 00:06:46.340 align:middle line:84% He spent-- I don't remember how long, 00:06:46.340 --> 00:06:49.940 align:middle line:84% but it was a couple of years, I think. 00:06:49.940 --> 00:06:53.380 align:middle line:84% And he wrote a book in 1983, very critical of Mead. 00:06:53.380 --> 00:06:57.120 align:middle line:84% So let's just go through Margaret Mead's claims 00:06:57.120 --> 00:06:59.720 align:middle line:84% that turned out to be much too extreme. 00:06:59.720 --> 00:07:03.160 align:middle line:84% So we want to know, how did she come to believe those claims? 00:07:03.160 --> 00:07:04.310 align:middle line:90% Why did she make errors? 00:07:04.310 --> 00:07:07.070 align:middle line:90% 00:07:07.070 --> 00:07:09.200 align:middle line:84% And we've already talked about Frank Boas 00:07:09.200 --> 00:07:10.210 align:middle line:90% and what he believed. 00:07:10.210 --> 00:07:12.980 align:middle line:84% And she was his student and she promoted those ideas 00:07:12.980 --> 00:07:13.760 align:middle line:90% in this book. 00:07:13.760 --> 00:07:18.180 align:middle line:90% 00:07:18.180 --> 00:07:23.160 align:middle line:84% She claimed that Samoan society is very different 00:07:23.160 --> 00:07:26.490 align:middle line:84% from our society, having very relaxed attitudes 00:07:26.490 --> 00:07:29.800 align:middle line:84% towards premarital sex by young women. 00:07:29.800 --> 00:07:35.160 align:middle line:84% And that used to be much stricter at the time she 00:07:35.160 --> 00:07:36.450 align:middle line:90% wrote that book-- 00:07:36.450 --> 00:07:41.250 align:middle line:84% far stricter than it is now in modern American society. 00:07:41.250 --> 00:07:44.380 align:middle line:84% She also claimed an absence of rape, freedom 00:07:44.380 --> 00:07:47.760 align:middle line:84% from emotional turbulence during adolescence. 00:07:47.760 --> 00:07:50.000 align:middle line:84% And remember, these were adolescent girls 00:07:50.000 --> 00:07:51.020 align:middle line:90% she was interviewing. 00:07:51.020 --> 00:07:54.390 align:middle line:90% 00:07:54.390 --> 00:07:56.570 align:middle line:90% So this is what she had done. 00:07:56.570 --> 00:08:00.870 align:middle line:84% At age 23, because of being told by 00:08:00.870 --> 00:08:04.870 align:middle line:84% other cultural anthropologists about Samoan society, 00:08:04.870 --> 00:08:07.930 align:middle line:84% she wanted to verify what they were believing. 00:08:07.930 --> 00:08:11.270 align:middle line:90% 00:08:11.270 --> 00:08:16.450 align:middle line:84% So she based the study on interviewing 25 young women. 00:08:16.450 --> 00:08:19.180 align:middle line:84% Now those 25 women, many of them-- 00:08:19.180 --> 00:08:23.810 align:middle line:84% most of them-- were still alive when Derek Freeman went there. 00:08:23.810 --> 00:08:27.630 align:middle line:84% So he talked to the very same women 00:08:27.630 --> 00:08:28.790 align:middle line:90% when they were much older. 00:08:28.790 --> 00:08:34.330 align:middle line:90% 00:08:34.330 --> 00:08:36.720 align:middle line:84% And as Freeman described, she didn't 00:08:36.720 --> 00:08:40.309 align:middle line:84% stay in Samoa for really extensive observations. 00:08:40.309 --> 00:08:43.360 align:middle line:84% She just believed what the girls told her. 00:08:43.360 --> 00:08:45.070 align:middle line:90% And they were often kidding her. 00:08:45.070 --> 00:08:48.340 align:middle line:84% [CHUCKLING] She heard what she wanted to hear. 00:08:48.340 --> 00:08:51.120 align:middle line:84% She wasn't critical in her method. 00:08:51.120 --> 00:08:54.700 align:middle line:90% 00:08:54.700 --> 00:08:59.185 align:middle line:84% And this belief of Boas is what she wanted to promote. 00:08:59.185 --> 00:09:04.570 align:middle line:90% 00:09:04.570 --> 00:09:06.050 align:middle line:84% There's certainly the same issues 00:09:06.050 --> 00:09:09.090 align:middle line:84% faced by sociobiologists since then, 00:09:09.090 --> 00:09:11.750 align:middle line:84% when they have applied the ideas and methods to humans. 00:09:11.750 --> 00:09:15.605 align:middle line:84% That's what got E.O. Wilson, we say, in such trouble. 00:09:15.605 --> 00:09:18.470 align:middle line:90% 00:09:18.470 --> 00:09:22.180 align:middle line:84% He was in trouble because he put a chapter on human society-- 00:09:22.180 --> 00:09:25.610 align:middle line:84% the very last chapter of the book-- 00:09:25.610 --> 00:09:32.640 align:middle line:84% applying sociobiology ideas to humans. 00:09:32.640 --> 00:09:36.910 align:middle line:84% I mean, the bulk of the book is about animal behavior-- 00:09:36.910 --> 00:09:40.750 align:middle line:84% animal social behavior in particular. 00:09:40.750 --> 00:09:42.760 align:middle line:84% So this is how I would summarize it all. 00:09:42.760 --> 00:09:44.850 align:middle line:84% She tried to do a scientific study. 00:09:44.850 --> 00:09:48.060 align:middle line:84% She was young, inexperienced, 23 years old. 00:09:48.060 --> 00:09:50.430 align:middle line:90% She made big mistakes. 00:09:50.430 --> 00:09:53.930 align:middle line:84% But her book became very popular and had a wide influence 00:09:53.930 --> 00:09:56.320 align:middle line:90% despite those errors. 00:09:56.320 --> 00:10:01.100 align:middle line:84% And the errors didn't really become well known until-- 00:10:01.100 --> 00:10:02.600 align:middle line:84% and I don't think they're well known 00:10:02.600 --> 00:10:04.665 align:middle line:90% now except among academics. 00:10:04.665 --> 00:10:07.780 align:middle line:90% 00:10:07.780 --> 00:10:08.965 align:middle line:90% And that took many years. 00:10:08.965 --> 00:10:16.150 align:middle line:90% 00:10:16.150 --> 00:10:21.540 align:middle line:84% So they obviously-- these cultural anthropologists-- 00:10:21.540 --> 00:10:25.090 align:middle line:84% had a blank-slate view of human nature. 00:10:25.090 --> 00:10:27.800 align:middle line:84% And we have talked about how that conflicts 00:10:27.800 --> 00:10:30.320 align:middle line:90% with sociobiological views. 00:10:30.320 --> 00:10:33.220 align:middle line:84% But what do blank-slate views of human nature 00:10:33.220 --> 00:10:36.235 align:middle line:84% actually predict about social structure and practices? 00:10:36.235 --> 00:10:40.410 align:middle line:90% 00:10:40.410 --> 00:10:44.730 align:middle line:84% And as we summarize that, just note 00:10:44.730 --> 00:10:53.260 align:middle line:84% that it's easy to make these ideas believable about humans, 00:10:53.260 --> 00:10:54.790 align:middle line:90% but not for animals. 00:10:54.790 --> 00:10:57.000 align:middle line:84% It's much more hard to make these predictions 00:10:57.000 --> 00:10:57.605 align:middle line:90% about animals. 00:10:57.605 --> 00:11:02.340 align:middle line:90% 00:11:02.340 --> 00:11:05.670 align:middle line:84% There's two new things here about this whole discussion. 00:11:05.670 --> 00:11:07.330 align:middle line:90% One is Gould's claim that-- 00:11:07.330 --> 00:11:11.040 align:middle line:90% 00:11:11.040 --> 00:11:14.680 align:middle line:84% he was criticized by sociobiologists 00:11:14.680 --> 00:11:17.510 align:middle line:84% for talking so much about biological determinism 00:11:17.510 --> 00:11:21.400 align:middle line:84% that he changed it to biological potentiality. 00:11:21.400 --> 00:11:23.300 align:middle line:84% So he claimed that a human has a brain 00:11:23.300 --> 00:11:26.000 align:middle line:84% capable of a full range of human behaviors 00:11:26.000 --> 00:11:29.910 align:middle line:90% and predisposed towards none. 00:11:29.910 --> 00:11:33.100 align:middle line:90% He was a biologist-- 00:11:33.100 --> 00:11:35.860 align:middle line:84% an evolutionary biologist-- writing regularly 00:11:35.860 --> 00:11:38.840 align:middle line:90% in the magazine Natural History. 00:11:38.840 --> 00:11:42.610 align:middle line:90% And he was very well known. 00:11:42.610 --> 00:11:45.040 align:middle line:84% And he sort of becomes a whipping boy in Alcock's book. 00:11:45.040 --> 00:11:48.900 align:middle line:90% 00:11:48.900 --> 00:11:51.710 align:middle line:84% The problem is, there was a lack of rigorous tests 00:11:51.710 --> 00:11:55.685 align:middle line:84% of the predictions of cultural determinism. 00:11:55.685 --> 00:12:01.410 align:middle line:84% And Alcock tries to suggest some predictions that the critic 00:12:01.410 --> 00:12:02.710 align:middle line:90% should be testing. 00:12:02.710 --> 00:12:06.420 align:middle line:84% And giving you where he does that, he basically 00:12:06.420 --> 00:12:09.630 align:middle line:84% says human behavior should differ greatly and arbitrarily 00:12:09.630 --> 00:12:11.920 align:middle line:90% from society to society. 00:12:11.920 --> 00:12:13.910 align:middle line:90% And he gives examples of that. 00:12:13.910 --> 00:12:15.990 align:middle line:90% Do you think that's true? 00:12:15.990 --> 00:12:19.740 align:middle line:84% Should societies differ arbitrarily? 00:12:19.740 --> 00:12:23.820 align:middle line:84% Well, there's got to be some constraints, right? 00:12:23.820 --> 00:12:29.190 align:middle line:84% But they claim there's no inheritance of behavior 00:12:29.190 --> 00:12:32.470 align:middle line:90% in humans, only in animals. 00:12:32.470 --> 00:12:33.460 align:middle line:90% Or at least not-- 00:12:33.460 --> 00:12:35.500 align:middle line:84% you know, when you start thinking about it, 00:12:35.500 --> 00:12:38.240 align:middle line:84% does that mean they don't believe that we 00:12:38.240 --> 00:12:41.940 align:middle line:90% inherit the ability to walk? 00:12:41.940 --> 00:12:44.550 align:middle line:90% I don't think so. 00:12:44.550 --> 00:12:46.130 align:middle line:84% But actually, most of them do believe 00:12:46.130 --> 00:12:50.560 align:middle line:84% we have to learn to walk, as I pointed out a number of times-- 00:12:50.560 --> 00:12:53.190 align:middle line:90% 00:12:53.190 --> 00:12:57.890 align:middle line:84% even though it's actually a fixed-action pattern, 00:12:57.890 --> 00:13:00.902 align:middle line:84% as many other things are in human, as well as 00:13:00.902 --> 00:13:01.735 align:middle line:90% in animal, behavior. 00:13:01.735 --> 00:13:05.770 align:middle line:90% 00:13:05.770 --> 00:13:08.350 align:middle line:90% So Alcock tries to apply that. 00:13:08.350 --> 00:13:12.490 align:middle line:84% And I think it's pretty interesting when you actually 00:13:12.490 --> 00:13:15.770 align:middle line:84% make the predictions and you look from society to society. 00:13:15.770 --> 00:13:19.750 align:middle line:84% And we find out that there are wide differences. 00:13:19.750 --> 00:13:26.790 align:middle line:84% But they're not arbitrary, random differences at all. 00:13:26.790 --> 00:13:31.680 align:middle line:84% So read that, and you will see exactly what I'm talking about. 00:13:31.680 --> 00:13:33.810 align:middle line:84% I'm not going to go over them now. 00:13:33.810 --> 00:13:35.820 align:middle line:84% It's very clear in Alcock's book. 00:13:35.820 --> 00:13:42.620 align:middle line:84% And you should be familiar with how difficult those predictions 00:13:42.620 --> 00:13:49.150 align:middle line:90% are to test. 00:13:49.150 --> 00:13:51.110 align:middle line:84% I'm sorry-- they're not difficult to test, 00:13:51.110 --> 00:13:53.865 align:middle line:84% they're difficult to verify, any of them. 00:13:53.865 --> 00:13:54.365 align:middle line:90% OK. 00:13:54.365 --> 00:13:57.040 align:middle line:90% 00:13:57.040 --> 00:14:00.595 align:middle line:84% We might not want to say that it's completely arbitrary. 00:14:00.595 --> 00:14:02.470 align:middle line:84% I don't know if any of them would claim that. 00:14:02.470 --> 00:14:04.830 align:middle line:90% But the way they talk-- 00:14:04.830 --> 00:14:07.240 align:middle line:84% maybe it's partly in the strength -- 00:14:07.240 --> 00:14:09.620 align:middle line:84% the vehemence-- of their opposition 00:14:09.620 --> 00:14:12.360 align:middle line:84% to sociobiology that they make these strong claims. 00:14:12.360 --> 00:14:17.080 align:middle line:90% 00:14:17.080 --> 00:14:18.960 align:middle line:90% All right. 00:14:18.960 --> 00:14:22.100 align:middle line:84% Let's talk about male-female attraction, 00:14:22.100 --> 00:14:24.860 align:middle line:84% because this is something that sociobiologists 00:14:24.860 --> 00:14:25.980 align:middle line:90% have dealt with. 00:14:25.980 --> 00:14:29.070 align:middle line:84% And they have dealt with it, as you know, in many animals. 00:14:29.070 --> 00:14:32.620 align:middle line:84% We talked about sexual selection. 00:14:32.620 --> 00:14:36.055 align:middle line:84% We've shown examples of it from, especially, bird behavior. 00:14:36.055 --> 00:14:38.900 align:middle line:90% 00:14:38.900 --> 00:14:43.390 align:middle line:84% There's a whole program on WGBH on love and animals, 00:14:43.390 --> 00:14:49.250 align:middle line:84% and many, many examples, not just from birds, 00:14:49.250 --> 00:14:52.900 align:middle line:84% about things males will do to be chosen by females-- 00:14:52.900 --> 00:14:56.200 align:middle line:84% a little bit on the other side, although often it's 00:14:56.200 --> 00:15:00.700 align:middle line:84% more on that than on the male mate choice. 00:15:00.700 --> 00:15:05.410 align:middle line:90% 00:15:05.410 --> 00:15:08.260 align:middle line:84% I just want you to note that when we go over this, 00:15:08.260 --> 00:15:13.180 align:middle line:84% it's not what's fashionable that matches what men actually 00:15:13.180 --> 00:15:16.700 align:middle line:90% prefer in a mate. 00:15:16.700 --> 00:15:19.475 align:middle line:84% And yet, what men actually prefer 00:15:19.475 --> 00:15:22.690 align:middle line:84% is the only thing of real interest to sociobiologists-- 00:15:22.690 --> 00:15:24.720 align:middle line:84% not what they say, not what modern fashion 00:15:24.720 --> 00:15:28.480 align:middle line:90% dictates, and so forth. 00:15:28.480 --> 00:15:30.810 align:middle line:84% There's a very easy example of that. 00:15:30.810 --> 00:15:35.390 align:middle line:84% Look at the difference between women 00:15:35.390 --> 00:15:38.370 align:middle line:84% that are pictured in fashion magazines and women 00:15:38.370 --> 00:15:41.580 align:middle line:84% that are pictured in the male pinup magazines, 00:15:41.580 --> 00:15:44.138 align:middle line:84% or whatever you want to call them. 00:15:44.138 --> 00:15:44.805 align:middle line:90% Big differences. 00:15:44.805 --> 00:15:47.360 align:middle line:90% 00:15:47.360 --> 00:15:47.860 align:middle line:90% OK. 00:15:47.860 --> 00:15:50.710 align:middle line:90% 00:15:50.710 --> 00:15:56.330 align:middle line:84% Also, we should note that there are societal differences. 00:15:56.330 --> 00:15:59.830 align:middle line:84% For example, in the poorer societies, 00:15:59.830 --> 00:16:01.100 align:middle line:90% women that are heavier-- 00:16:01.100 --> 00:16:03.560 align:middle line:84% that is, a higher body mass index, 00:16:03.560 --> 00:16:09.690 align:middle line:84% and we'll talk about that in a minute, 00:16:09.690 --> 00:16:12.555 align:middle line:84% may indicate greater wealth, and therefore be attractive. 00:16:12.555 --> 00:16:15.210 align:middle line:90% 00:16:15.210 --> 00:16:17.210 align:middle line:84% When I first went to India, I realized 00:16:17.210 --> 00:16:26.400 align:middle line:84% that it doesn't apply so much to the very wealthy in India. 00:16:26.400 --> 00:16:30.420 align:middle line:84% But if you deal with the bulk of the people, 00:16:30.420 --> 00:16:34.870 align:middle line:84% women that are heavier are often preferred, 00:16:34.870 --> 00:16:39.030 align:middle line:84% because it indicates that they must have more resources. 00:16:39.030 --> 00:16:41.260 align:middle line:84% You think that would apply even more to men-- 00:16:41.260 --> 00:16:42.620 align:middle line:90% men being heavier. 00:16:42.620 --> 00:16:46.850 align:middle line:84% But they always talk about the women. 00:16:46.850 --> 00:16:47.450 align:middle line:90% All right. 00:16:47.450 --> 00:16:52.720 align:middle line:90% 00:16:52.720 --> 00:16:56.660 align:middle line:84% In Alcock, and we'll take a look at-- 00:16:56.660 --> 00:17:00.180 align:middle line:84% I didn't actually copy the table for the slides. 00:17:00.180 --> 00:17:01.830 align:middle line:84% But many of you have looked at it. 00:17:01.830 --> 00:17:02.930 align:middle line:90% You've read this chapter. 00:17:02.930 --> 00:17:03.740 align:middle line:90% Table 7-1. 00:17:03.740 --> 00:17:05.730 align:middle line:90% It's on page 138. 00:17:05.730 --> 00:17:10.079 align:middle line:84% He goes through attributes in women that men find attractive. 00:17:10.079 --> 00:17:13.339 align:middle line:90% And what is their meaning? 00:17:13.339 --> 00:17:14.800 align:middle line:90% What is their signal value? 00:17:14.800 --> 00:17:19.630 align:middle line:84% What is that property of a woman's body signal? 00:17:19.630 --> 00:17:22.119 align:middle line:84% And he says all the attributes listed 00:17:22.119 --> 00:17:27.000 align:middle line:84% indicate health, fertility, sexual maturity, and youth? 00:17:27.000 --> 00:17:28.890 align:middle line:90% OK? 00:17:28.890 --> 00:17:32.080 align:middle line:84% They're all, together, predictors of lifetime 00:17:32.080 --> 00:17:33.980 align:middle line:90% reproductive potential. 00:17:33.980 --> 00:17:36.820 align:middle line:84% And you must keep in mind when you look at these things, 00:17:36.820 --> 00:17:38.100 align:middle line:90% that there's always a range. 00:17:38.100 --> 00:17:41.280 align:middle line:84% There's always exceptions to the general rule. 00:17:41.280 --> 00:17:44.750 align:middle line:84% Sociobiological hypotheses are not about "always," 00:17:44.750 --> 00:17:46.885 align:middle line:84% and they're not disproved by "sometimes." 00:17:46.885 --> 00:17:51.140 align:middle line:90% 00:17:51.140 --> 00:17:56.220 align:middle line:84% So this first attribute is smooth, unblemished skin, 00:17:56.220 --> 00:17:59.870 align:middle line:84% indicates youthfulness and good health. 00:17:59.870 --> 00:18:02.822 align:middle line:84% And he lists-- he gives references for studies 00:18:02.822 --> 00:18:04.030 align:middle line:90% of that, that have been done. 00:18:04.030 --> 00:18:06.870 align:middle line:90% Symmetrical faces and limbs. 00:18:06.870 --> 00:18:10.940 align:middle line:84% Indicates developmental stability, good genes, 00:18:10.940 --> 00:18:15.860 align:middle line:84% good nutritional experience during development . 00:18:15.860 --> 00:18:17.786 align:middle line:84% Then one he calls facial averageness. 00:18:17.786 --> 00:18:21.080 align:middle line:90% 00:18:21.080 --> 00:18:26.030 align:middle line:84% Indicates optimum normal development and resistance 00:18:26.030 --> 00:18:26.585 align:middle line:90% to parasites. 00:18:26.585 --> 00:18:28.880 align:middle line:90% [LAUGHTER] 00:18:28.880 --> 00:18:30.700 align:middle line:84% Prominent-- you know, you don't think 00:18:30.700 --> 00:18:33.380 align:middle line:84% much if you don't have that much trouble with parasites. 00:18:33.380 --> 00:18:37.480 align:middle line:84% But it's big problems for many groups, 00:18:37.480 --> 00:18:40.530 align:middle line:84% and certainly was in our evolution. 00:18:40.530 --> 00:18:42.250 align:middle line:90% Prominent cheekbones. 00:18:42.250 --> 00:18:43.970 align:middle line:90% Indicates sexual maturity. 00:18:43.970 --> 00:18:47.120 align:middle line:84% Cheekbones of mature women are quite different than when 00:18:47.120 --> 00:18:49.160 align:middle line:90% they were younger. 00:18:49.160 --> 00:18:52.860 align:middle line:84% Small chin, small nose, large eyes, full lips. 00:18:52.860 --> 00:18:56.490 align:middle line:84% Indicates high estrogen levels during development 00:18:56.490 --> 00:18:58.680 align:middle line:90% and youthfulness. 00:18:58.680 --> 00:19:05.710 align:middle line:90% Waste-to-hip ratio of 0.7. 00:19:05.710 --> 00:19:09.900 align:middle line:84% Indicates current high estrogen levels, ample fat reserves, 00:19:09.900 --> 00:19:12.155 align:middle line:84% in good health, higher probability 00:19:12.155 --> 00:19:15.690 align:middle line:84% of becoming pregnant, lower probability of early mortality. 00:19:15.690 --> 00:19:19.240 align:middle line:90% 00:19:19.240 --> 00:19:23.710 align:middle line:84% There have been many studies of that and arguments about it. 00:19:23.710 --> 00:19:26.670 align:middle line:84% But the average in what men prefer always 00:19:26.670 --> 00:19:33.180 align:middle line:90% comes out to be above 0.7. 00:19:33.180 --> 00:19:36.210 align:middle line:84% I remember reading one of the very early studies of that. 00:19:36.210 --> 00:19:39.590 align:middle line:84% It was done by a woman from India-- 00:19:39.590 --> 00:19:43.270 align:middle line:84% very nice study, where she made this whole science 00:19:43.270 --> 00:19:47.250 align:middle line:90% into a quantitative science. 00:19:47.250 --> 00:19:49.530 align:middle line:84% Large, firm, symmetrical breasts indicates 00:19:49.530 --> 00:19:52.730 align:middle line:84% developmental stability, youthfulness, and immune system 00:19:52.730 --> 00:19:53.820 align:middle line:90% competence. 00:19:53.820 --> 00:19:56.820 align:middle line:90% And a body mass index-- 00:19:56.820 --> 00:20:00.240 align:middle line:84% in this table he says 20 to 24, the preferred range 00:20:00.240 --> 00:20:02.500 align:middle line:90% is actually 17 to 24. 00:20:02.500 --> 00:20:05.150 align:middle line:84% Indicates high fertility and low mortality rates. 00:20:05.150 --> 00:20:07.180 align:middle line:84% And you notice, that is a big range-- 00:20:07.180 --> 00:20:08.210 align:middle line:90% 17 to 24. 00:20:08.210 --> 00:20:10.900 align:middle line:90% 00:20:10.900 --> 00:20:15.390 align:middle line:84% We'll talk a little more about this body mass index. 00:20:15.390 --> 00:20:19.390 align:middle line:90% But right here-- 00:20:19.390 --> 00:20:21.680 align:middle line:84% I pulled a table out of Wikipedia. 00:20:21.680 --> 00:20:31.830 align:middle line:90% 00:20:31.830 --> 00:20:33.700 align:middle line:84% I'd point out here at the top, there's 00:20:33.700 --> 00:20:37.110 align:middle line:84% variability in measures of the relative importance 00:20:37.110 --> 00:20:42.020 align:middle line:84% of different factors, especially in these two-- 00:20:42.020 --> 00:20:44.760 align:middle line:84% body mass index and the waist-to-hip ratio. 00:20:44.760 --> 00:20:46.470 align:middle line:84% So we'll talk a little more about that. 00:20:46.470 --> 00:20:52.480 align:middle line:84% But these are the usual classifications-- 00:20:52.480 --> 00:20:55.690 align:middle line:84% from severely underweight, and underweight to normal, 00:20:55.690 --> 00:20:56.350 align:middle line:90% and then over. 00:20:56.350 --> 00:20:59.330 align:middle line:84% And notice the normal range is pretty big-- 00:20:59.330 --> 00:21:01.540 align:middle line:90% 18 and 1/2 to 25. 00:21:01.540 --> 00:21:03.960 align:middle line:84% How do you compute your body mass index? 00:21:03.960 --> 00:21:08.620 align:middle line:84% You might all be curious what your body mass index is. 00:21:08.620 --> 00:21:14.550 align:middle line:84% Well, notice it's in kilograms per meter squared-- 00:21:14.550 --> 00:21:18.380 align:middle line:90% meter of height. 00:21:18.380 --> 00:21:20.740 align:middle line:90% OK. 00:21:20.740 --> 00:21:25.020 align:middle line:84% So you have to convert your weight in pounds to kilograms 00:21:25.020 --> 00:21:26.690 align:middle line:90% to get this measure. 00:21:26.690 --> 00:21:33.650 align:middle line:84% And you convert your height to meters. 00:21:33.650 --> 00:21:36.670 align:middle line:84% And then you come out with these numbers. 00:21:36.670 --> 00:21:39.410 align:middle line:84% And most of you, I'm sure, will fall in this range. 00:21:39.410 --> 00:21:40.645 align:middle line:90% You can have to 25. 00:21:40.645 --> 00:21:45.000 align:middle line:90% 00:21:45.000 --> 00:21:47.670 align:middle line:90% And yes, I'm not underweight. 00:21:47.670 --> 00:21:49.580 align:middle line:90% I'm actually in this range. 00:21:49.580 --> 00:21:50.620 align:middle line:90% I'm at the low end. 00:21:50.620 --> 00:21:51.230 align:middle line:90% [LAUGHTER] 00:21:51.230 --> 00:21:52.200 align:middle line:90% OK. 00:21:52.200 --> 00:21:57.470 align:middle line:84% And then, notice all these categories 00:21:57.470 --> 00:21:58.570 align:middle line:90% for being overweight. 00:21:58.570 --> 00:22:01.440 align:middle line:84% Overweight, obese class one, obese class two, 00:22:01.440 --> 00:22:08.283 align:middle line:84% severely obese, morbidly obese, super obese, and hyper obese. 00:22:08.283 --> 00:22:09.700 align:middle line:84% And notice, these are the weights. 00:22:09.700 --> 00:22:13.010 align:middle line:90% 00:22:13.010 --> 00:22:21.570 align:middle line:84% Someone that's 5' 11", 1.8 meters. 00:22:21.570 --> 00:22:25.990 align:middle line:90% OK, so if they're 5' 11"-- 00:22:25.990 --> 00:22:31.980 align:middle line:90% very tall woman, average man-- 00:22:31.980 --> 00:22:33.990 align:middle line:84% these are the weights they have to be 00:22:33.990 --> 00:22:36.350 align:middle line:90% to have that body mass index. 00:22:36.350 --> 00:22:42.770 align:middle line:84% And the males always prefer, as I pointed out before, 17 to 24. 00:22:42.770 --> 00:22:47.270 align:middle line:84% So they prefer women to be from at the top end 00:22:47.270 --> 00:22:51.965 align:middle line:84% of the underweight range to near the top of normal. 00:22:51.965 --> 00:22:58.220 align:middle line:90% 00:22:58.220 --> 00:23:02.870 align:middle line:84% So then he cites this British study, 1998, 00:23:02.870 --> 00:23:07.260 align:middle line:84% of preferences shown by British male undergraduates. 00:23:07.260 --> 00:23:08.140 align:middle line:90% This is the title. 00:23:08.140 --> 00:23:11.570 align:middle line:84% Optimum Body Mass Index and Maximum Sexual Attractiveness. 00:23:11.570 --> 00:23:16.490 align:middle line:90% 00:23:16.490 --> 00:23:19.530 align:middle line:84% And they claim-- and this shows you the controversy-- 00:23:19.530 --> 00:23:23.190 align:middle line:84% because there have been many studies of waist-to-hip ratio 00:23:23.190 --> 00:23:25.930 align:middle line:84% as the big factor for attractiveness. 00:23:25.930 --> 00:23:28.675 align:middle line:84% They found that the BMI was a much better predictor 00:23:28.675 --> 00:23:31.760 align:middle line:84% than the waist-to-hip ratio, even 00:23:31.760 --> 00:23:34.820 align:middle line:84% though other studies haven't shown such a difference. 00:23:34.820 --> 00:23:38.758 align:middle line:84% In fact, the ratio has often been reported 00:23:38.758 --> 00:23:39.800 align:middle line:90% to be the most important. 00:23:39.800 --> 00:23:43.360 align:middle line:84% So I'm going to go through one of those interesting studies 00:23:43.360 --> 00:23:45.260 align:middle line:90% next. 00:23:45.260 --> 00:23:47.360 align:middle line:84% I think there's plenty of evidence 00:23:47.360 --> 00:23:49.770 align:middle line:90% that both factors are important. 00:23:49.770 --> 00:23:54.120 align:middle line:84% But in their study, the range was 17 to 24. 00:23:54.120 --> 00:23:57.050 align:middle line:90% 00:23:57.050 --> 00:23:58.590 align:middle line:84% And I point out the numbers there 00:23:58.590 --> 00:24:02.950 align:middle line:90% for both those type of values. 00:24:02.950 --> 00:24:06.000 align:middle line:90% But there are exceptions. 00:24:06.000 --> 00:24:14.350 align:middle line:84% And one is the group of Yomibato, South American tribe. 00:24:14.350 --> 00:24:16.930 align:middle line:84% It was found that they tend to prefer females 00:24:16.930 --> 00:24:18.865 align:middle line:90% with a figure that's heavier-- 00:24:18.865 --> 00:24:25.200 align:middle line:84% with a larger waist-to-hip ratio than what is preferred by most 00:24:25.200 --> 00:24:32.010 align:middle line:84% men in what we call advanced cultures-- 00:24:32.010 --> 00:24:37.550 align:middle line:84% advanced technically, educationally, so forth. 00:24:37.550 --> 00:24:41.610 align:middle line:90% And I didn't bring the pictures. 00:24:41.610 --> 00:24:45.500 align:middle line:84% They show silhouettes of the kind of women. 00:24:45.500 --> 00:24:47.480 align:middle line:84% Basically these men in the test were 00:24:47.480 --> 00:24:53.110 align:middle line:84% shown little drawings of women, mostly front view, 00:24:53.110 --> 00:24:54.530 align:middle line:90% so you can see their shape. 00:24:54.530 --> 00:24:57.500 align:middle line:84% And they chose the slightly heavier 00:24:57.500 --> 00:25:03.280 align:middle line:84% than what people in the USA or Europe would choose. 00:25:03.280 --> 00:25:04.700 align:middle line:90% So he suggests-- 00:25:04.700 --> 00:25:06.650 align:middle line:84% I think his argument is a little bit fuzzy, 00:25:06.650 --> 00:25:08.775 align:middle line:90% and it hasn't been fully tested. 00:25:08.775 --> 00:25:12.980 align:middle line:84% But he points out that obesity was 00:25:12.980 --> 00:25:17.650 align:middle line:84% all but impossible in pre-colonial Amerindian groups. 00:25:17.650 --> 00:25:20.403 align:middle line:84% These were American and American Indian groups in South America. 00:25:20.403 --> 00:25:23.190 align:middle line:90% 00:25:23.190 --> 00:25:25.740 align:middle line:84% Being underweight was probably more common. 00:25:25.740 --> 00:25:28.540 align:middle line:84% And if a woman was slightly overweight, 00:25:28.540 --> 00:25:31.040 align:middle line:84% he suggests that there was a greater probability 00:25:31.040 --> 00:25:34.320 align:middle line:90% of her being fertile. 00:25:34.320 --> 00:25:36.170 align:middle line:84% And also the probability would be 00:25:36.170 --> 00:25:39.040 align:middle line:84% greater that she doesn't have a problem with parasites, 00:25:39.040 --> 00:25:45.800 align:middle line:84% which are common down in there, with their living style. 00:25:45.800 --> 00:25:48.850 align:middle line:84% And, of course, that suggestion should apply to other groups. 00:25:48.850 --> 00:25:50.035 align:middle line:90% That should be more tested. 00:25:50.035 --> 00:25:56.570 align:middle line:90% 00:25:56.570 --> 00:25:59.030 align:middle line:84% And it should at least be true for groups that have been 00:25:59.030 --> 00:26:00.580 align:middle line:90% isolated from modern societies. 00:26:00.580 --> 00:26:04.670 align:middle line:90% 00:26:04.670 --> 00:26:06.030 align:middle line:90% We don't know. 00:26:06.030 --> 00:26:07.870 align:middle line:90% He's probably right about this. 00:26:07.870 --> 00:26:11.890 align:middle line:84% But, you know, you need to test any of these ideas. 00:26:11.890 --> 00:26:13.940 align:middle line:84% But you could also just say, well, OK, 00:26:13.940 --> 00:26:19.010 align:middle line:84% one exception doesn't disprove the general finding. 00:26:19.010 --> 00:26:20.440 align:middle line:84% And even though that's true, when 00:26:20.440 --> 00:26:23.313 align:middle line:84% you get a consistent finding like that in one society, 00:26:23.313 --> 00:26:24.730 align:middle line:84% there's got be some reason for it. 00:26:24.730 --> 00:26:29.350 align:middle line:84% And so it's worthy of more investigation. 00:26:29.350 --> 00:26:32.290 align:middle line:84% But not just with the Yomibato, but with other groups where 00:26:32.290 --> 00:26:33.835 align:middle line:90% similar conditions apply. 00:26:33.835 --> 00:26:37.410 align:middle line:90% 00:26:37.410 --> 00:26:43.060 align:middle line:84% OK, now this is a study where they paid attention 00:26:43.060 --> 00:26:45.900 align:middle line:90% to both of these measures. 00:26:45.900 --> 00:26:47.040 align:middle line:90% This is the article. 00:26:47.040 --> 00:26:50.110 align:middle line:84% Male Preferences for Female Waist-to-Hip Ratio 00:26:50.110 --> 00:26:53.800 align:middle line:84% and Body Mass Index in the Highlands of Papua New Guinea. 00:26:53.800 --> 00:26:58.830 align:middle line:90% 00:26:58.830 --> 00:27:01.400 align:middle line:84% It was published in the American Journal of Physical 00:27:01.400 --> 00:27:03.510 align:middle line:90% Anthropology a few years ago. 00:27:03.510 --> 00:27:08.220 align:middle line:90% 00:27:08.220 --> 00:27:14.060 align:middle line:84% They were using 100 men in three villages in this remote region. 00:27:14.060 --> 00:27:16.270 align:middle line:84% They were asked to judge attractiveness 00:27:16.270 --> 00:27:21.440 align:middle line:84% of women who had undergone micrograph surgery to reduce 00:27:21.440 --> 00:27:23.350 align:middle line:90% their waste-to-hip ratio. 00:27:23.350 --> 00:27:25.480 align:middle line:84% They had undergone a kind of plastic surgery. 00:27:25.480 --> 00:27:28.410 align:middle line:90% 00:27:28.410 --> 00:27:32.060 align:middle line:84% So what they do is, they take the fatty tissue, 00:27:32.060 --> 00:27:34.710 align:middle line:84% the adipose tissue, from the waist, 00:27:34.710 --> 00:27:36.700 align:middle line:84% and reshape the buttocks with it. 00:27:36.700 --> 00:27:40.220 align:middle line:84% So the weight-- the average weight, anyway-- of these women 00:27:40.220 --> 00:27:42.740 align:middle line:90% doesn't change much. 00:27:42.740 --> 00:27:43.785 align:middle line:90% But their shape changes. 00:27:43.785 --> 00:27:46.570 align:middle line:90% 00:27:46.570 --> 00:27:48.880 align:middle line:84% They get more of an hour-glass figure. 00:27:48.880 --> 00:27:52.610 align:middle line:84% And the men consistently chose post-operative photographs 00:27:52.610 --> 00:27:56.370 align:middle line:84% as being more attractive than pre-operative photographs 00:27:56.370 --> 00:27:57.160 align:middle line:90% of the same women. 00:27:57.160 --> 00:28:00.030 align:middle line:90% 00:28:00.030 --> 00:28:01.980 align:middle line:84% And it didn't seem to be the body mass 00:28:01.980 --> 00:28:03.270 align:middle line:90% index that made a difference. 00:28:03.270 --> 00:28:06.980 align:middle line:84% These are the actual numbers from the study. 00:28:06.980 --> 00:28:11.650 align:middle line:90% And they did it twice. 00:28:11.650 --> 00:28:17.110 align:middle line:84% These are the two groups of women undergoing the surgery. 00:28:17.110 --> 00:28:22.955 align:middle line:84% This gives the patients' ethnicity. 00:28:22.955 --> 00:28:24.740 align:middle line:90% And you can see that varied. 00:28:24.740 --> 00:28:28.410 align:middle line:90% 00:28:28.410 --> 00:28:35.800 align:middle line:84% And in this group, you can see that the body mass 00:28:35.800 --> 00:28:36.685 align:middle line:90% index was not-- 00:28:36.685 --> 00:28:41.233 align:middle line:90% 00:28:41.233 --> 00:28:42.900 align:middle line:84% one group actually went up a little bit, 00:28:42.900 --> 00:28:45.150 align:middle line:84% the other group went down a little bit-- the body mass 00:28:45.150 --> 00:28:45.940 align:middle line:90% index. 00:28:45.940 --> 00:28:48.450 align:middle line:84% But the waist- to-hip ratios that you can see, 00:28:48.450 --> 00:28:51.293 align:middle line:90% were consistently reduced. 00:28:51.293 --> 00:28:59.520 align:middle line:90% 00:28:59.520 --> 00:29:00.020 align:middle line:90% All right. 00:29:00.020 --> 00:29:03.170 align:middle line:90% So that was the data they had. 00:29:03.170 --> 00:29:05.720 align:middle line:84% And the men were tested on photographs. 00:29:05.720 --> 00:29:07.760 align:middle line:84% These are the nature of the photographs. 00:29:07.760 --> 00:29:09.740 align:middle line:90% So here's pre-op. 00:29:09.740 --> 00:29:12.080 align:middle line:90% Here's post-op. 00:29:12.080 --> 00:29:15.590 align:middle line:90% And this is the oblique view-- 00:29:15.590 --> 00:29:16.850 align:middle line:90% pre-op and post-op. 00:29:16.850 --> 00:29:19.295 align:middle line:84% So it shows what the surgeons were doing. 00:29:19.295 --> 00:29:20.545 align:middle line:90% And these are the preferences. 00:29:20.545 --> 00:29:23.130 align:middle line:90% 00:29:23.130 --> 00:29:27.160 align:middle line:84% Much greater preference for the post-operative-- 00:29:27.160 --> 00:29:31.310 align:middle line:90% similarly for that view. 00:29:31.310 --> 00:29:33.820 align:middle line:84% So that was one study that, because they were 00:29:33.820 --> 00:29:35.940 align:middle line:90% the very same women involved-- 00:29:35.940 --> 00:29:39.500 align:middle line:84% the only thing that was changing in an obvious way 00:29:39.500 --> 00:29:43.970 align:middle line:84% was simply that shape that affected 00:29:43.970 --> 00:29:46.090 align:middle line:90% their waste-to-hip ratio. 00:29:46.090 --> 00:29:50.063 align:middle line:84% The body mass index, when it did go down, 00:29:50.063 --> 00:29:51.480 align:middle line:84% didn't seem to make any difference 00:29:51.480 --> 00:29:52.780 align:middle line:90% in that particular study. 00:29:52.780 --> 00:29:56.770 align:middle line:90% 00:29:56.770 --> 00:30:00.520 align:middle line:84% So what about preferences shown by females choosing mates. 00:30:00.520 --> 00:30:02.330 align:middle line:90% This has been studied also. 00:30:02.330 --> 00:30:09.040 align:middle line:84% And as we know from when we were talking about Scott's chapters, 00:30:09.040 --> 00:30:11.450 align:middle line:84% that females tend to make their decisions 00:30:11.450 --> 00:30:12.870 align:middle line:90% by different kinds of means. 00:30:12.870 --> 00:30:16.000 align:middle line:90% 00:30:16.000 --> 00:30:18.615 align:middle line:84% It doesn't mean that physical attractiveness does not 00:30:18.615 --> 00:30:19.490 align:middle line:90% make some difference. 00:30:19.490 --> 00:30:22.710 align:middle line:84% But it is often not nearly as important for women 00:30:22.710 --> 00:30:24.760 align:middle line:90% as it is for a man. 00:30:24.760 --> 00:30:26.830 align:middle line:84% And there's reasons-- evolutionary reasons-- 00:30:26.830 --> 00:30:27.800 align:middle line:90% for that. 00:30:27.800 --> 00:30:31.375 align:middle line:90% Women prefer resource potential. 00:30:31.375 --> 00:30:34.010 align:middle line:90% 00:30:34.010 --> 00:30:36.140 align:middle line:84% And so you'd predict that, well, they 00:30:36.140 --> 00:30:38.457 align:middle line:84% might prefer slightly older men, more likely 00:30:38.457 --> 00:30:40.165 align:middle line:90% to have more resources. 00:30:40.165 --> 00:30:42.875 align:middle line:90% 00:30:42.875 --> 00:30:49.150 align:middle line:84% They are more likely to prefer rich men, and so forth-- 00:30:49.150 --> 00:30:51.820 align:middle line:90% men with property. 00:30:51.820 --> 00:30:54.602 align:middle line:84% Most men at the age when these choices are made 00:30:54.602 --> 00:30:56.435 align:middle line:84% don't actually have property in our society. 00:30:56.435 --> 00:30:59.180 align:middle line:90% 00:30:59.180 --> 00:31:01.960 align:middle line:84% But anyway, that's how I would expect them to differ. 00:31:01.960 --> 00:31:10.780 align:middle line:84% And if you look at the term "maximum reproductive 00:31:10.780 --> 00:31:13.940 align:middle line:84% potential," it just has a different meaning 00:31:13.940 --> 00:31:15.820 align:middle line:90% for women and men. 00:31:15.820 --> 00:31:18.535 align:middle line:84% And this is the difference in age preferences-- 00:31:18.535 --> 00:31:21.200 align:middle line:90% 00:31:21.200 --> 00:31:22.650 align:middle line:90% the mean age. 00:31:22.650 --> 00:31:24.015 align:middle line:90% This is the age difference-- 00:31:24.015 --> 00:31:27.310 align:middle line:90% 00:31:27.310 --> 00:31:30.380 align:middle line:90% male greater than female. 00:31:30.380 --> 00:31:33.090 align:middle line:84% It's only these to the left of that vertical line 00:31:33.090 --> 00:31:37.480 align:middle line:84% there, where in actual marriages, 00:31:37.480 --> 00:31:41.210 align:middle line:84% the male is younger than the female. 00:31:41.210 --> 00:31:43.700 align:middle line:84% These are all the ones where the male is older. 00:31:43.700 --> 00:31:48.850 align:middle line:84% And note that the peak is roughly three years. 00:31:48.850 --> 00:31:51.410 align:middle line:84% That's a consistent finding in these studies. 00:31:51.410 --> 00:31:53.640 align:middle line:90% But notice also a huge range. 00:31:53.640 --> 00:31:57.220 align:middle line:90% 00:31:57.220 --> 00:31:59.130 align:middle line:90% It goes up, of course. 00:31:59.130 --> 00:32:02.230 align:middle line:84% Some women will marry a man that's 00:32:02.230 --> 00:32:03.630 align:middle line:90% more than twice their age. 00:32:03.630 --> 00:32:06.490 align:middle line:84% And this does occur, so all that kind of data 00:32:06.490 --> 00:32:08.870 align:middle line:90% is on this type of curve. 00:32:08.870 --> 00:32:13.970 align:middle line:84% But you can see, it's a small, small percentage there. 00:32:13.970 --> 00:32:17.540 align:middle line:84% So it's explained-- it's predicted-- 00:32:17.540 --> 00:32:21.310 align:middle line:84% by this expectation that women are looking more 00:32:21.310 --> 00:32:25.500 align:middle line:84% for potential or actual resources. 00:32:25.500 --> 00:32:26.030 align:middle line:90% All right. 00:32:26.030 --> 00:32:29.130 align:middle line:90% 00:32:29.130 --> 00:32:36.470 align:middle line:84% Humans also have this tendency to stay and act within groups. 00:32:36.470 --> 00:32:38.660 align:middle line:84% And different groups may compete with each other, 00:32:38.660 --> 00:32:39.525 align:middle line:90% sometimes violently. 00:32:39.525 --> 00:32:45.330 align:middle line:90% 00:32:45.330 --> 00:32:49.250 align:middle line:84% Remember the story of Romeo and Juliet. 00:32:49.250 --> 00:32:57.500 align:middle line:84% So I want to try to specify a list of evolutionary fitness 00:32:57.500 --> 00:33:01.320 align:middle line:84% benefits of these groupism feelings. 00:33:01.320 --> 00:33:04.270 align:middle line:90% Why do we like to measure-- 00:33:04.270 --> 00:33:07.220 align:middle line:84% to choose someone within our group-- 00:33:07.220 --> 00:33:09.960 align:middle line:84% especially if you think of earlier society 00:33:09.960 --> 00:33:12.090 align:middle line:90% during our evolution. 00:33:12.090 --> 00:33:13.090 align:middle line:90% OK. 00:33:13.090 --> 00:33:16.530 align:middle line:84% And these are the things I could come up with. 00:33:16.530 --> 00:33:18.796 align:middle line:84% Higher probability of finding a mate. 00:33:18.796 --> 00:33:21.320 align:middle line:90% 00:33:21.320 --> 00:33:26.380 align:middle line:84% Higher probability of rescue and survival 00:33:26.380 --> 00:33:29.630 align:middle line:90% if you stay within that group. 00:33:29.630 --> 00:33:34.060 align:middle line:84% Higher probability of better defense against predators. 00:33:34.060 --> 00:33:35.050 align:middle line:90% If there's a predator-- 00:33:35.050 --> 00:33:40.360 align:middle line:84% people in the same group get together, help each other-- 00:33:40.360 --> 00:33:44.480 align:middle line:84% not as likely to help the outsider. 00:33:44.480 --> 00:33:46.950 align:middle line:84% Higher probability of a better defense 00:33:46.950 --> 00:33:50.840 align:middle line:90% against hostile human groups. 00:33:50.840 --> 00:33:55.790 align:middle line:84% Advantages in food acquisition, gathering, hunting, sharing 00:33:55.790 --> 00:33:57.330 align:middle line:90% and specialization. 00:33:57.330 --> 00:33:59.880 align:middle line:84% These are all advantages of being in a group. 00:33:59.880 --> 00:34:02.090 align:middle line:84% Help in child-rearing and education. 00:34:02.090 --> 00:34:05.330 align:middle line:90% 00:34:05.330 --> 00:34:08.650 align:middle line:84% And advantages in learning from older, more experienced group 00:34:08.650 --> 00:34:10.960 align:middle line:90% members. 00:34:10.960 --> 00:34:14.608 align:middle line:84% It's much easier within your group than for someone 00:34:14.608 --> 00:34:15.400 align:middle line:90% from another group. 00:34:15.400 --> 00:34:18.250 align:middle line:90% 00:34:18.250 --> 00:34:20.780 align:middle line:84% Of course, now we've formalized education so much. 00:34:20.780 --> 00:34:23.854 align:middle line:84% We cross these boundaries all the time. 00:34:23.854 --> 00:34:29.239 align:middle line:84% At least during our evolution, these probably all 00:34:29.239 --> 00:34:31.510 align:middle line:90% would be true-- 00:34:31.510 --> 00:34:34.400 align:middle line:84% which would simply explain why we've evolved 00:34:34.400 --> 00:34:35.525 align:middle line:90% these kinds of feelings. 00:34:35.525 --> 00:34:39.580 align:middle line:90% 00:34:39.580 --> 00:34:40.080 align:middle line:90% OK. 00:34:40.080 --> 00:34:46.929 align:middle line:84% Then we get to his appendix questions 00:34:46.929 --> 00:34:52.330 align:middle line:84% about the biological basis for reciprocity among humans. 00:34:52.330 --> 00:34:53.735 align:middle line:84% The claim is it remains unproven. 00:34:53.735 --> 00:34:57.200 align:middle line:90% 00:34:57.200 --> 00:35:00.350 align:middle line:84% Here the statement is that general self interest 00:35:00.350 --> 00:35:02.750 align:middle line:84% and an ability to see beyond the short term, 00:35:02.750 --> 00:35:06.170 align:middle line:84% may be all that's required to generate such behavior. 00:35:06.170 --> 00:35:09.590 align:middle line:84% So what's the misunderstanding in that kind of statement? 00:35:09.590 --> 00:35:11.090 align:middle line:90% It's very simple. 00:35:11.090 --> 00:35:15.410 align:middle line:84% They confuse proximate and ultimate issues. 00:35:15.410 --> 00:35:19.530 align:middle line:84% As we know from before, you have to deal with those things 00:35:19.530 --> 00:35:20.500 align:middle line:90% separately. 00:35:20.500 --> 00:35:23.940 align:middle line:84% Understand that they're separate kinds of issues. 00:35:23.940 --> 00:35:28.860 align:middle line:90% 00:35:28.860 --> 00:35:30.680 align:middle line:84% What about the idea of languages? 00:35:30.680 --> 00:35:33.420 align:middle line:84% Languages vary greatly among human societies. 00:35:33.420 --> 00:35:35.690 align:middle line:84% So if someone claims that this fact clearly 00:35:35.690 --> 00:35:38.260 align:middle line:84% demonstrates the greater importance of culture 00:35:38.260 --> 00:35:40.910 align:middle line:84% than biology in the control of human behavior, 00:35:40.910 --> 00:35:43.740 align:middle line:84% how does a sociobiologist deal with that? 00:35:43.740 --> 00:35:45.610 align:middle line:90% Very simply. 00:35:45.610 --> 00:35:49.390 align:middle line:84% The important issue is language versus no language, 00:35:49.390 --> 00:35:52.390 align:middle line:84% not the details of a particular language. 00:35:52.390 --> 00:35:55.110 align:middle line:84% That's where Chomsky made a great contribution, 00:35:55.110 --> 00:36:01.880 align:middle line:84% pointing out the form of grammar that's the same in one language 00:36:01.880 --> 00:36:03.200 align:middle line:90% after another after another. 00:36:03.200 --> 00:36:08.860 align:middle line:90% 00:36:08.860 --> 00:36:13.010 align:middle line:84% So we're born with an innate ability to learn any language. 00:36:13.010 --> 00:36:14.400 align:middle line:90% That's what we inherit. 00:36:14.400 --> 00:36:19.380 align:middle line:90% 00:36:19.380 --> 00:36:25.770 align:middle line:84% And here's one of Stephen Jay Gould's statements. 00:36:25.770 --> 00:36:29.090 align:middle line:84% "Men are not programmed by genes to maximize matings, 00:36:29.090 --> 00:36:34.110 align:middle line:84% nor are women devoted to monogamy by inalterable nature. 00:36:34.110 --> 00:36:37.870 align:middle line:84% We can speak only of capacities, not requirements or even 00:36:37.870 --> 00:36:40.050 align:middle line:90% determining propensities. 00:36:40.050 --> 00:36:44.540 align:middle line:84% Therefore, our biology does not make us do it." 00:36:44.540 --> 00:36:46.100 align:middle line:84% So how do you deal with that kind 00:36:46.100 --> 00:36:47.450 align:middle line:90% of criticism of sociobiology? 00:36:47.450 --> 00:36:53.520 align:middle line:90% 00:36:53.520 --> 00:36:55.640 align:middle line:84% He's pitting culture against biology. 00:36:55.640 --> 00:36:57.380 align:middle line:90% Culture versus biology. 00:36:57.380 --> 00:37:02.570 align:middle line:84% It's not an either/or matter at all. 00:37:02.570 --> 00:37:04.710 align:middle line:84% As we pointed out, both are always involved. 00:37:04.710 --> 00:37:15.120 align:middle line:90% 00:37:15.120 --> 00:37:17.800 align:middle line:90% OK, now this is interesting. 00:37:17.800 --> 00:37:20.340 align:middle line:90% This is a critique of Alcock. 00:37:20.340 --> 00:37:22.260 align:middle line:84% In the final paragraph of chapter seven, 00:37:22.260 --> 00:37:25.570 align:middle line:84% he sums up his conclusions about the unlikely philosophy 00:37:25.570 --> 00:37:29.570 align:middle line:84% that Gould, Mead and many social scientists and some feminists 00:37:29.570 --> 00:37:33.690 align:middle line:84% would have us accept, largely on ideological grounds. 00:37:33.690 --> 00:37:35.860 align:middle line:84% But then he suddenly shifts the argument. 00:37:35.860 --> 00:37:38.930 align:middle line:90% And listen to what he says. 00:37:38.930 --> 00:37:41.970 align:middle line:84% "That this position has any residual credibility 00:37:41.970 --> 00:37:45.660 align:middle line:84% can be attributed largely to the power of wishful thinking 00:37:45.660 --> 00:37:50.430 align:middle line:84% that some special meaning accrues to human existence." 00:37:50.430 --> 00:37:52.210 align:middle line:90% And this is a quote now. 00:37:52.210 --> 00:37:55.880 align:middle line:84% "It is not easy to accept that evolution is a meaningless tale 00:37:55.880 --> 00:37:57.830 align:middle line:90% told by an idiot." 00:37:57.830 --> 00:37:59.530 align:middle line:90% His conclusion is then stated. 00:37:59.530 --> 00:38:01.860 align:middle line:84% "Indeed most people find it hard to believe 00:38:01.860 --> 00:38:05.570 align:middle line:84% the blind evolutionary processes have created 00:38:05.570 --> 00:38:07.850 align:middle line:84% us, a creature whose unconscious ultimate 00:38:07.850 --> 00:38:10.710 align:middle line:84% goal is no different from that of the slime 00:38:10.710 --> 00:38:14.630 align:middle line:84% mold, the aardvark, the pine tree, and the earthworm. 00:38:14.630 --> 00:38:19.780 align:middle line:84% Although this point is evidently unpalatable, 00:38:19.780 --> 00:38:22.670 align:middle line:90% it is true nevertheless." 00:38:22.670 --> 00:38:26.330 align:middle line:84% So my criticism of Alcock here is just 00:38:26.330 --> 00:38:28.850 align:middle line:84% his very narrow definition of what 00:38:28.850 --> 00:38:30.590 align:middle line:90% you mean by an ultimate goal. 00:38:30.590 --> 00:38:33.530 align:middle line:90% 00:38:33.530 --> 00:38:37.050 align:middle line:84% There's the ultimate reason we evolved this way-- 00:38:37.050 --> 00:38:43.510 align:middle line:84% certainly this very simple rule of maximizing genetic fitness. 00:38:43.510 --> 00:38:46.200 align:middle line:90% 00:38:46.200 --> 00:38:50.550 align:middle line:84% So is it really a meaningless tale told by an idiot? 00:38:50.550 --> 00:38:54.020 align:middle line:84% In my view, what is really incredible and amazing 00:38:54.020 --> 00:38:58.250 align:middle line:84% is that the simple and repeated process of genetic spread 00:38:58.250 --> 00:39:01.005 align:middle line:84% and change, following the biological law 00:39:01.005 --> 00:39:04.670 align:middle line:84% of natural selection, has led to such complex creatures 00:39:04.670 --> 00:39:08.410 align:middle line:84% with such cognitive capacities, and with such an ability 00:39:08.410 --> 00:39:10.910 align:middle line:84% to ponder the nature of the world and its beings. 00:39:10.910 --> 00:39:16.700 align:middle line:84% And beyond that, I would add that conscious beings-- 00:39:16.700 --> 00:39:19.030 align:middle line:84% the sociobiologist, the evolutionist, 00:39:19.030 --> 00:39:22.890 align:middle line:84% they have no explanation for even the existence 00:39:22.890 --> 00:39:25.260 align:middle line:90% of consciousness. 00:39:25.260 --> 00:39:30.170 align:middle line:84% It's outside their realm, as I pointed out before. 00:39:30.170 --> 00:39:32.710 align:middle line:90% OK, here's a final topic. 00:39:32.710 --> 00:39:35.300 align:middle line:90% We have four minutes. 00:39:35.300 --> 00:39:38.860 align:middle line:90% Romantic love. 00:39:38.860 --> 00:39:41.230 align:middle line:84% Is the phenomenon of romantic love-- 00:39:41.230 --> 00:39:42.800 align:middle line:90% the falling-in-love experience-- 00:39:42.800 --> 00:39:45.900 align:middle line:84% an invention of medieval court life, 00:39:45.900 --> 00:39:51.410 align:middle line:84% as has been repeatedly asserted in literature? 00:39:51.410 --> 00:39:58.500 align:middle line:84% And it's a very popular belief after it was first proposed. 00:39:58.500 --> 00:40:02.280 align:middle line:84% Does it only occur in certain cultures? 00:40:02.280 --> 00:40:06.860 align:middle line:84% So I want to state a sociobiological hypothesis 00:40:06.860 --> 00:40:09.010 align:middle line:90% concerning its origins. 00:40:09.010 --> 00:40:10.810 align:middle line:84% Because you're working on another homework, 00:40:10.810 --> 00:40:14.420 align:middle line:84% on your topics, I'm not going to give this as a homework. 00:40:14.420 --> 00:40:17.510 align:middle line:84% I'm going to give you what I would say about it. 00:40:17.510 --> 00:40:20.250 align:middle line:90% 00:40:20.250 --> 00:40:26.810 align:middle line:84% First of all, I would say that the idea was invented 00:40:26.810 --> 00:40:30.790 align:middle line:84% by people who could not accept the role of innate motivations 00:40:30.790 --> 00:40:31.900 align:middle line:90% in humans at all. 00:40:31.900 --> 00:40:34.910 align:middle line:84% And there are many people like that. 00:40:34.910 --> 00:40:36.170 align:middle line:90% OK. 00:40:36.170 --> 00:40:38.660 align:middle line:84% Does it occur only in certain cultures? 00:40:38.660 --> 00:40:41.480 align:middle line:84% It appears to occur in all cultures to some degree. 00:40:41.480 --> 00:40:46.770 align:middle line:84% And there are many cultures that have marriages 00:40:46.770 --> 00:40:53.630 align:middle line:84% that are made by the-- basically all the decisions are 00:40:53.630 --> 00:40:56.550 align:middle line:84% by the parents and the relatives. 00:40:56.550 --> 00:41:01.380 align:middle line:84% But even in those cultures, they end up having to separate-- 00:41:01.380 --> 00:41:03.940 align:middle line:84% well, this was an arranged marriage 00:41:03.940 --> 00:41:06.190 align:middle line:90% and that is a love marriage. 00:41:06.190 --> 00:41:08.540 align:middle line:90% They separate them. 00:41:08.540 --> 00:41:13.837 align:middle line:84% And you find that in all these cultures, 00:41:13.837 --> 00:41:15.420 align:middle line:84% because falling in love still happens. 00:41:15.420 --> 00:41:18.430 align:middle line:90% 00:41:18.430 --> 00:41:21.990 align:middle line:84% Fortunately, in societies where the marriages are decided 00:41:21.990 --> 00:41:26.050 align:middle line:84% by parents, they often work out better than marriages here, 00:41:26.050 --> 00:41:29.700 align:middle line:84% where the rate of divorce is now greater than 50%. 00:41:29.700 --> 00:41:32.950 align:middle line:90% 00:41:32.950 --> 00:41:36.150 align:middle line:84% But let's state a sociobiological hypothesis 00:41:36.150 --> 00:41:40.210 align:middle line:84% about the origins of that feeling. 00:41:40.210 --> 00:41:43.720 align:middle line:90% It's clearly instinctive. 00:41:43.720 --> 00:41:47.430 align:middle line:84% If you haven't experienced it, you 00:41:47.430 --> 00:41:52.170 align:middle line:84% will realize when it does occur, that it's an innate-- 00:41:52.170 --> 00:41:53.820 align:middle line:90% something's happening to you. 00:41:53.820 --> 00:41:56.460 align:middle line:90% 00:41:56.460 --> 00:41:59.030 align:middle line:84% Does it occur only in young people? 00:41:59.030 --> 00:42:00.320 align:middle line:90% No. 00:42:00.320 --> 00:42:03.100 align:middle line:84% Are prominent leaders in the community exempt? 00:42:03.100 --> 00:42:06.030 align:middle line:84% There's plenty of examples in the news where that's not true. 00:42:06.030 --> 00:42:08.660 align:middle line:90% 00:42:08.660 --> 00:42:11.610 align:middle line:84% If it has evolved as a human fixed-action pattern, 00:42:11.610 --> 00:42:16.730 align:middle line:84% it's got to be adaptive in a sociobiological sense. 00:42:16.730 --> 00:42:20.510 align:middle line:84% Like many evolved tendencies, it can produce conflicts, 00:42:20.510 --> 00:42:23.200 align:middle line:84% not only in the society but within the individual. 00:42:23.200 --> 00:42:26.920 align:middle line:84% And this can cause what we call cognitive dissonance which 00:42:26.920 --> 00:42:28.960 align:middle line:84% the individual will struggle to resolve 00:42:28.960 --> 00:42:32.180 align:middle line:90% in one way or the other. 00:42:32.180 --> 00:42:35.540 align:middle line:84% So consider why it must have had to evolve 00:42:35.540 --> 00:42:37.930 align:middle line:90% in early human groups. 00:42:37.930 --> 00:42:40.910 align:middle line:84% Think of the close bonds acquired 00:42:40.910 --> 00:42:44.590 align:middle line:84% in growing up in an extended family, 00:42:44.590 --> 00:42:51.060 align:middle line:84% within which there were very bad consequences of inbreeding. 00:42:51.060 --> 00:42:53.560 align:middle line:84% It was necessary for genetic fitness 00:42:53.560 --> 00:42:57.810 align:middle line:84% to have a motivation that could occur in strength 00:42:57.810 --> 00:42:59.270 align:middle line:90% after sexual maturity-- 00:42:59.270 --> 00:43:01.220 align:middle line:84% strong enough to cause a young person 00:43:01.220 --> 00:43:05.050 align:middle line:90% to leave his natal group. 00:43:05.050 --> 00:43:09.480 align:middle line:84% And the result was what they often 00:43:09.480 --> 00:43:11.450 align:middle line:84% call "roaming in search of a mate"-- 00:43:11.450 --> 00:43:13.280 align:middle line:90% a very common tradition. 00:43:13.280 --> 00:43:16.650 align:middle line:84% Usually the male-- but not always just the male-- 00:43:16.650 --> 00:43:18.090 align:middle line:90% will go off in search of a mate. 00:43:18.090 --> 00:43:24.650 align:middle line:84% He leaves home till he finds a woman he can fall for. 00:43:24.650 --> 00:43:28.680 align:middle line:84% You also have secret liaisons, eloping, 00:43:28.680 --> 00:43:31.500 align:middle line:84% all the other characteristics of the falling-in-love phenomena, 00:43:31.500 --> 00:43:34.170 align:middle line:84% including behaving stupidly, irrationally, 00:43:34.170 --> 00:43:37.510 align:middle line:84% disregarding long-established habits, and everything. 00:43:37.510 --> 00:43:39.650 align:middle line:90% It has a biological reason. 00:43:39.650 --> 00:43:42.350 align:middle line:90% 00:43:42.350 --> 00:43:44.310 align:middle line:84% And then I'll let you just read these. 00:43:44.310 --> 00:43:48.540 align:middle line:84% I've put a few summaries of recent research, 00:43:48.540 --> 00:43:51.320 align:middle line:90% and they're very easy to find.