Families and Couples (UCLA)

Lecture 3

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Benjamin Karney: First of all we have a couple of announcements. Uh, last week we didn't have our TA with us she was off at a professional conference contributing to the growth of human knowledge but today she's back, and I'd like to introduce her to you. She is, uh, Lisa Liu, Lisa would you like to stand up and just wave to the class. This is our TA, you've got one so if, let's say you need to discuss something about the course, how it's organized or a question, a content issue in the course and I am a, uh, indisposed, feel free to contact Lisa Liu, her office hours are printed in the syllabus her e-mail is also there so, uh, that's just another resource to help you navigate this course. I'll tell you just a, uh brief story it has nothing to do with anything but I, I, um, I got a call from a journalist from San Diego asking me if I'd heard about an intimate relationships course that was being offered at UCSD and I said, "No, tell me about it," and she said in this course the instructor has randomly paired up students in the class and has them do exercises that will make them fall in love that will make, he's doing exercises, having people do exercises that he believes will, according to research, will inspire two people who do not know each other to fall in love with each other and I said and she wanted to know if I thought that was ethical and I, uh, I think it is probably not ethical although, you know, love is a good thing, it's just messing with people's lives. When we get to attraction we will talk about that research a little bit more. But today we're not talking about that. Today I want to pick up something, Leo a question. The mike's not on? Something's on. But now it's on. How about now? How about now? All right. Remember I said, uh, last week that my optometrist had come up to me and said, "Oh, I've got a theory about intimate relationships," and pointed out that everybody has a theory about intimate relationships. But you might ask yourself why does everyone have a theory about intimate relationships? What's the point? Why would it be that an optometrist would have a theory about intimate relationships? He doesn't have a theory about necessarily a theory about every other social phenomenon, why a theory about intimate relationships? And the answer is that we can't operate without theories of the world. And since intimate relationships are such a big part of our world, we can't operate without theories of intimate relationships. Now you might say, "Well that's not true, I approach my intimate relationships objectively like a scientist," at which point I might turn around and say "Oh, but scientists need theories more than anyone." And you might say, "Well, shouldn't a theory be a product of your science?" You don't want to start off with a theory and then do science to prove your theory. You want to do science objectively, collect the information and then create a theory that, that sort of explains the data. Well that's really not the way science works. Science doesn't end with a theory, it typically starts with a theory. And it was a mathematician who pointed this out very nicely, where he said "Science is indeed built up of facts, as a house is built up of stones. But an accumulation of facts is no more a science than a heap of stones is a house." In other words understanding intimate relationships requires a lot more from us than gathering a bunch of facts and observations about intimate relationships. What we need are theories that help give shape to the facts that we collect. And theories, uh, of intimate relationships are our topic today. We'll talk about a couple of big ones but first I want to say, a few more words on, what is a theory? And what's a good theory supposed to do? How are we supposed to judge what a theory of relationships is supposed to do? Let's start just with the idea of what's a theory? Uh, we'll define a theory as an interconnected set of beliefs, knowledge and assumptions, that relate to understanding a phenomenon. Well that's pretty broad. I mean that, by that definition almost anything is a theory. And, uh, that's exactly the point. Any set of interconnected beliefs, knowledge and assumptions represents a theory. Well you all have a set of beliefs, knowledge and assumptions about intimate relationships, that means each of has a theory right now about intimate relationships. And so does my optometrist, and so does my dad, and so do all of your optometrists, and all of your dads. Everyone has a theory, everyone, if you have any knowledge at all then that means, that's your theory. Now some theories are more articulate than others. Some theories are more explicit than others. Some people write down their theories and have a manifesto that says this is what I believe. Other people just have sort of vague notions and they couldn't even articulate them if you asked them to. But they are all theories. Because theories are sort of where we start. And if a theory is where we start, in a theory is also a map. A theory is our, um, our current map of the world. And if we're, we're thinking about the part of the world that's intimate relationships, then our theory is our current map of intimate relationships. We'll what does a map do? A map tells us what to expect, tells us what the landmarks are, tells us, it's a guide, and that's what our theory is. Our theory, our personal theories, your theory right now of intimate relationships is your map of intimate relationships. It's your guide to understanding what happens in intimate relationships. Right now you have a theory that if your partner buys you flowers, that means something. Now you might not all have the same theory. Some people might think, well, if my partner buys me flowers, that means my partner wants something from me and I should be suspicious. And other people might have a theory that, oh, if my partner buys me flowers that means that my partner appreciates me. Those would be different theories of relationships. Well the point is that in, in both cases, your theory is your map, that guides your behavior, that tells you what to do next. And as you might imagine some maps are better than others. You can imagine I might have a really detailed map with every single road and its just built to scale. Or I might have a hastily scrawled map on the back of a, of a napkin that leaves out details that is not to scale, that's distorted. Theories are the same way. Some theories might be really accurate depictions of the landscape of intimate relationships some theories, some theories might be really poor or distorted descriptions of the landscape of intimate relationships. But they're all theories and they all do the same things. Well, let's be a little bit more explicit about what theories do. What is a good theory? Well, one thing a theory does is it organizes existing knowledge, in other words like Pon Carre said, we don't just have an accumulation of facts, but they're organized. Some facts are more important than others. How do we know? Our theory tells us so. Our theories of intimate relationships let us know these are the important things to know about relationships. For example, most theories of intimate relationships think that it's pretty important how people treat each other. It's a theory that guides us to focus on some things and not the, and not other things. To say some knowledge is going to be important and some is less important. So one is it organizes our knowledge and then it draws attention to important processes. Today I'm going to talk about a handful of, and we're actually going to talk about actually two big theories of intimate relationships, and on Friday, I'm going to talk about, if my wife hasn't had her child yet, our child yet, then, uh, we're going to talk about three more. And each one of them draws attention to different important processes. A theory should explain something, should answer a question. A theory exists to answer questions for us. And it should answer it in a way that's elegant, that's parsimonious. The word parsimonious means to say a lot with a little. To, to have a lot of meaning in a very small amount of words or symbols. A theory does that for us. Uh, do you, do you know comedian Steven Wright? Uh, he made a point about, about, uh, building a map that was, where the scale was 1:1. Well, a 1:1 map, where every inch on the map the corresponds to a really inch in the real world, would be the real world. The point of a map is that it's parsimonious. It expresses the details of the real world in less detail than the real world. Well, a theory does the same thing. A theory reduces, somehow, the complexity of intimate relationships to something more manageable. It simplifies it. Every theory simplifies. But that's it’s point. A theory, a good theory will identify predictions and hypotheses. A good theory explains what we know and points the direction to what we don't know. A good theory makes predictions. A good theory says this is what will happen in the future. And you'll see that all the theories that I talk about this week, do this. Finally if you're a researcher, and of course we all are, a theory guides measurement decisions. A theory says, here's what you should measure. Here's what you should focus on as a scientist. So some theories will say, focus on behavior. Some theories will say, get at people's personality. That's what's gonna matter. Some theories are going to say, talk about what people experience in their childhood. Well, your different theory is going to ask different questions, and point you in different directions, for what matters. Again if the theory tells you what's important, that's going to tell you what to measure. And finally a theory, a good theory is a living thing. It improves on previous theory and it can itself be improved upon. Perhaps you've heard people talk about a theory as non-falsifiable. And non-falsifiable theory is a theory that cannot be changed by any observation. No observation would change your mind. So for example, here's a theory that is non-falsifiable. Relationships work when they are destined to work, when they are fated to work, that's my theory. Well, what makes a theory, what makes a relationship successful, you ask me, I'll tell you, fate and destiny. If they're destined to work, they will, if they're not destined to work, they won't. That's a theory, it's a real theory. But is it a good theory? Well, here's the problem. What data would, uh, allow us to make a prediction of whether people were destined or not? Unfortunately the only data such a theory would require is whether they succeeded or failed. If you know in advance, if you know afterwards, oh, that relationship broke up, you can say, oh, they weren't destined. And if they stay together, well, yup, that's destiny. Well that's not good enough, that's not a good theory. Because there's, there's no, you can't evolve, the theory cannot evolve, the theory cannot be affected by the data. As opposed to a good theory, can be wrong. In fact, good theory will be wrong, by definition because it's a simplification. It won't be perfect. All we can do is get closer and closer and closer to describing the real world. All right, so that's a good theory generally. But we don't want just any good theory, we want a good theory of intimate relationships. And that has to go a little bit farther. A good theory of intimate relationships has to do, I'm just going to say, three things. For one thing I want a good theory to do is, I want it to encompass a full range of possible predictors. What do I mean by that? What I mean by that is, we have a sense that a lot of things affect relationships, and I want a good theory to put it all together for me. So for example again, uh, I want a good theory to build me a house out of the specific stones of facts. And I want every stone to be used. So I think that people's relationships are somehow a function of their biology. I think that people's relationships are somehow a function of whether they're getting what they need. I think relationships, relationships are a function of, uh, how people treat each other, and their personalities and the, the, the world they live in. And I want my theory to put that all together, to leave nothing out. To encompass the full range of all the things we can imagine that affect relationships and to tell me how it fits together. And that's not all I want a theory to do. I also want a theory to specify mechanisms of change. As we talked about the first day, and as I'm now realizing we're going to be talking about every day, relationships change. That's the phenomena. It would be kind of interesting if some relationships were all good and stayed good, and some relationships were bad and stayed bad. But what's really interesting is that good relationships sometimes stay good and frequently go bad. That's the mystery. How does that happen? It's easy for a theory, and there's many theories out there that say, here's the difference between a good and a bad relationship. Duh, that's not good enough. I want a mechanism of change. And I also want a theory that does more than says, oh, sometimes relationships go bad. That's a description not a theory. I want a theory that says how is it, that some people who are in love end up not in love anymore. Mechanism of change. Where does change come from? But that's not all I want a theory to do. I also want this. I want the theory to show why different people and different couples have different experiences. That's a high bar to cross, because there's different kinds of variability. There's variability between couples. Some couples do better and worse than others. That's sort the easier kind of variability. Sure, you imagine you got two people who have a lot of problems in their lives, they're going to have a worse relationship than two people who have, you know, a lot of advantages in their lives. And I want to understand that. But I also want to understand variability within couples over time. And that's the mystery we keep hitting on. I want to understand how is it that couples have good days and bad days, or good months and bad months. How is it that the same two people go through a bad patch and get better. Or start out terrific and get worse. Or go back and forth. Have you ever known a relationship that, boy, these people sometimes are lovey-dovey, sometimes they're cats and dogs, they're fighting with each other, and they're back again. I've seen relationships like that. The good theory is going to explain all the phenomena, including variability within a couple. Those are pretty high standards. But in the field of intimate relationships, people have proposed some big ideas. Some big theories. And in our book, and in this set of two lectures, I'm going to tell you about five of these theories. Two today and three on Friday. And each of these theories, the people who write, who've written about these theories have said, in print, in one way or another, my theory is all you need to know. It's the theory. It's the comprehensive theory. And I'll tell you in advance that, that, that's probably not true. Probably each of these theories has a bit of the truth. But they've all, I've, I've, I choose to share them with you because they all ask the big questions, they all try to do these three things, with varying degrees of success, and they've all inspired a lot of the research that we’ll be talking about in the subsequent eight weeks of this course. So this is sort of the foundational week. Where we're going to talk about some of the biggest ideas in understanding intimate relationships. And we’re going to be playing out and fleshing out these ideas over the rest of the eight weeks of this course. So, I'm, you should be so happy that you're here and paying attention today because this sort of sets the groundwork for what we'll be doing. And in a way, the five theories can be organized on a continuum based on how far back in human history they search for the causes of human behavior. Of, and, and specifically behavior in intimate relationships. So let's start with the first theory that goes the farthest back, and as we progress through the theories, we'll get closer and closer in time. So the theory that really starts us at the earliest part is evolutionary theory. Well, you know about evolutionary theory, of course. You know about Charles Darwin, and the voyage of the Beagle, and the Galapagos Island turtles, and how Charles Darwin in his theory of natural selection said, not just humanity but all animal species, all living species evolved, through natural selection. And what's natural selection? The idea that there is variability in each generation. And some of those variations make people more likely to pass on their genes to the next generation. And so those variations should be passed on and gradually species change and develop. Well, evolutionary theory has been adapted to study psychological issues and, in particular, has been applied to the study of intimate relationships. And one of the people who's done it is a fellow named David Buss. And David Buss is a professor at the University of Texas. And I've met him exactly once, and this is how the meeting went. Uh, I had a private, I'd been given 30 minutes alone with David Buss, and I had recently published my own, uh, work on intimate relationships, I was still a graduate student at the time and, uh, I had talked about, tried to be comprehensive, I tried to specify mechanisms of change, I tried to put it all together and said this is it, the big picture of intimate relationships. And he came down, came into the room, sat himself down, and he said, "I've taken a look at your work and I want to know this, how do you account for the fact that women get less attractive as they get older?" And I said, "Uh, uh, what do you mean?" He said, "Well, they do." And I said, "Well, maybe they do, but, um, uh, so?" And he said, "Well, isn't that it? I mean, men are attracted to women when they're young then, of course relationships go bad because, uh, women get less attractive when they get older. And over time, men are not going to be satisfied with them." I said, to David Buss, who's been married more than once, well I said to him, uh, "That may be true on average, but some people stay together. And some people break up after a long time, and some people break up after a short time and it's that variability that I'm interested in." But it wasn't what he was interested in. Because his theory told him what he was interested in. And that wasn't it. And his theory says this. This is the premise briefly, I'm going to flesh this out. But, the premise, if you are to summarize theory in one word, one sentence, this is it. Humans seek particular mates to solve specific adaptive problems that their ancestors confronted during the course of human evolution. Human-mate preferences and mate decisions, are hypothesized to be strategic products of selection pressures operating during ancestral conditions. Well, what does that mean? What is he talking about? Because this is it, this is the premise of the evolutionary perspective on intimate relationships. And what is he talking about, well here's what he's talking about. What he's saying is that just as certain traits are passed down across generations because they help us survive, that we're more likely to survive if we have these traits, and that's natural selection. There are other traits that get passed down because they make us more likely to have sex, and therefore reproduce. So when you think of natural selection, you think of like survival of the fittest, whatever makes you more likely to survive, is likely to get passed down to the next generation. And that's true. But there's lots of things that get passed down in animal species that don't seem to contribute to survival, and yet they still get passed down. Case in point. Have you ever seen a male peacock? Sure you have. A male peacock has this beautiful plumage, this big, wide, beautiful, uh, tails, feathers, with the eyes, they're just gorgeous. Well how does that help a peacock survive? And the answer is, it doesn't help a peacock survive. In fact it impedes survival because it's big, and it makes, it slows the peacock down. If there's a tiger chasing that peacock, the ones with the biggest tail feathers will not escape the tiger, and yet it still evolved. So how, how is it that something so impractical, something so unwieldy would have evolved? The idea of sexual selection is that some things evolve because, even if they make us, even if they don't improve survival rates they do improve reproduction rates. And of course in the peacocks men, male peacocks, attract female pea-hens. That's right, a female peacock is a pea-hen, did you know that? Maybe you did know that. Anyway, uh, they, um, the more, the bigger, the fluffier, the more gorgeous the tail feathers the more likely you are to attract a pea-hen, therefore you reproduce, therefore the ones with the biggest tail feathers passed their traits of big tail feathers on to the next generation. Well, so in animals, so in peacocks, says evolutionary perspectives on intimate relationships, so in human beings. Sexual selection should absolutely operate in human beings, as well. Such that whatever traits, preferences, tendencies contributed to successful reproduction to, that, result in surviving offspring, whatever those preferences are that contribute to successful reproduction, those should be passed down. And, therefore, us human beings should be the products of generation upon generation of sexual selection. Therefore, our preferences, when it comes to sex when it comes to mate selection, they're not just random. But rather they're strategic. They are things that we, as a human species evolved, to solve reproductive problems that we faced when the human species was evolving. Now, biological types have looked at this and said, well, you know, maybe that explains a lot of things about the human, about human physiology, about the way that we, uh, respond sexually, but the evolutionary psychologists, focus specifically on the evolution of what's called psychological mechanisms. A psychological mechanism is a tendency to think and respond a certain way, in the presence of certain stimuli. Now the word mechanism makes this sound very robotic, the idea, we don't like the idea, that, oh, I'm not a mechanism, I have free will, I respond flexibly to things. Well, the evolutionary psychologists don't really mean that this is a deterministic mechanism. But they ask a question, the evolutionary psychologists ask a question, which is this, why do we find youth attractive? Why? Why are people who are sort of young, and have good clean skin, why is that attractive? And you might say, well, obviously it's attractive, you know, it's more attractive to have, for example, the evolutionary psychologists, I'll get to you in a second. The evolutionary psychologists ask this question, why is clean skin sexier than oozing, festering sores. Well, you're like, you’re laughing, cause obviously no one wants a big, puffy, oozing sore for a partner. But why exactly why? I mean, it's not, I mean, it's, maybe it seems obvious, but why? Well, the evolutionary psychologist says, back in evolutionary times, let's say there were two cavemen. One of them really loved oozing, festering sores. And the other one really loved clean, fresh skin. Well, it so happens that people who have clean, fresh skin tend to be healthier. They're more likely to reproduce successfully. So that preference for clean, fresh skin was more likely to lead to successful reproduction, whereas the guy who was only reproducing with the people with oozing, festering sores, well, those kids didn't survive very long. So we evolved, a preference for youth, for health, for fresh, clean skin. Do you have a question? What's your name?

Luigi: Luigi

Benjamin Karney: Luigi:

Luigi: Is it maybe that youth is more, like, fertile?

Benjamin Karney: Absolutely, absolutely, so the idea being that, well, let's say there's two cavemen, and one of them really likes people who are sort of old and wizened. And the other one likes people who are young and just at the, just coincidentally at reproductive age. Well, that person who's attracted to young people of reproductive age is going to reproduce more often and more successfully. So the preference will get passed down. Now, a psychological mechanism gets passed, the idea is that a psychological mechanism gets passed down across generations in the same way that brown hair gets passed down across generations. Or tallness, or straight teeth. Now, we can probably, we're closer to identifying the genes for straight teeth than we are to identifying the gene for preferring a particular mate over another particular mate. And that's OK. The evolutionary psychologist says, I'm not sure what the gene is for a particular psychological mechanism. All I can tell you is there is a psychological mechanism, in this case it would be a preference for a certain kind of mate over another kind, and gets passed down. Or it got passed down, and, now, that's what we're left with. What they are is preferences, tendencies in the human species, what they're not is deterministic or mechanistic. Here's another thing that they're not necessarily. Psychological mechanisms are not necessarily conscious. Well, you know, maybe they are conscious, in that is I know none of you is, it's quite conscious in that, yeah, I prefer no festering sores. Please. Most people prefer straight teeth over crooked teeth. Most people prefer signs of health than signs of sickness. Well that's conscious and, uh, the evolutionary psychologist says that a psychological mechanism. That preference is a psychological mechanism and it serves an adaptive function. It means that we're going to seek out mates that are maximally likely to help us reproduce successfully. Now here's the interesting thing. Here's the interesting thing. Evolution takes a long time to work itself out. A long time. Changes evolve in a species, let's say the human species, slowly, mighty slowly. And the implication of that fact is that in terms of evolutionary history, it's been an eye blink, since we were all wearing skins, living in caves, with a lot more hair on our bodies and thick ridges over our eyebrows. From an evolutionary perspective we're just, it was just yesterday that we were all Neanderthals. And if that's true, says the evolutionary psychologists, and if we, in fact, have evolved psychological mechanisms, then these evolved psychological mechanisms did not evolve to adapt us to today's environment because, in evolutionary terms, today's environment has barely started to exist. No, we have evolved not to adapt to this environment of UCLA but rather, to adapt to the environment of evolutionary adaptiveness. In other words to adapt, we've adapted our mechanisms to fit the environment where we all evolved from, in caves with, wearing saber tooth tiger skins. I'm exaggerating a little bit. But you get the flavor of it. So the evolutionary psychologist is making a very interesting point. Which is that, with respect to our psychological mechanisms, we are all cave people. Therefore, if you want to understand our current day's psychological mechanisms, if you want to understand how the human species evolved, what preferences the human species has, then you don't want to look at today. You want to look at history, you want to look at the environment of evolutionary adaptiveness, and ask yourself, what preferences would have evolved in that environment? What was adaptive back then? And that's how evolutionary psychology proceeds. Evolutionary psychology proceeds basically by conducting, at first, thought experiments. Saying, okay, let's think about it. What was that environment like? What were the adaptive challenges that the human species had respond to? And what, what would have been a, uh, strategic clever way to pass on your genes? It's likely that we would have evolved psychological mechanisms, that are responsive to those challenges. And since no time has passed at all since then, we're going to still have those psychological mechanisms. Mechanisms that are adapted to that environment. The environment of 30, 40,000 years ago. You're with me so far? And let's think about. What were the challenges? What were the challenges that human beings faced with respect to reproduction and mate selection in that environment? Well, there's actually a sub-theory, of evolutionary theory that addresses this exact question. And that theory is called the theory of parental investment. And the theory of parental investment does what I just described, it thinks back, it says, okay, there we are, we're all living in caves. What's the challenge? What's the issue? And the theory of parental investment says a lot of the challenges around human reproduction and mate selection arise from this fact. The fact that, by virtue of biology, men and women invest in the next generation in different ways. And I can tell you I'm experiencing this right now, in my house. The theory of parental investment says let's take a look at the situation and adaptive challenges that women face. A woman unlike, a, a female dog, or some female fish, can only gestate, most of the time, one child at a time. You know, fish can have plenty of eggs at the same time, a female dog can have a litter of puppies. Human beings, except for that crazy lady that lives nearby, uh, uh, most of the time one, maybe two, most of the time one baby at the time. And how long does it take to nurture that baby? Nine months. And, and during that nine months, that woman is increasingly immobile, and cannot have other, cannot gestate other children, she can take care of existing children, but she cannot gestate other children. So for nine months, your reproductive capacity is tied into, tied up into one single child. Now, from an evolutionary standpoint, your goal, if you're the mother of the child is, support this child. And how are you going to do it? Well you want to try to find a mate that will (a) be healthy and fit, so that this child is likely to be healthy and fit, (b) you want a mate that can protect your child from predators and (c) you want a mate who's going to, help this, help you with this child even after the child comes out. So if you have two cavewomen, with different preferences, the one who reproduces the most successfully, is the one who has the preferences that attract her towards mates that solve those problems. So what would you expect? You would expect over the course of generations for females of the species to evolve psychological mechanisms that alert them to the presence of men who are healthy, men who are strong, men who have the capacity to protect the mother and the child. What about men, in the same environment of evolutionary adaptiveness? What, what are men's challenges? Men's challenges are quite different because their investment in parenthood is different. A man's investments in creating an offspring is sperm. And men have plenty of sperm. Moreover, whereas a women can only be impregnated once for nine months at a time, a man can impregnate many, many people simultaneously. With very little effort. In fact even by accident. So men, what are men looking for? Well, for men the challenge is to get access to as many people as possible because the more people I have access to, the more genes I'll have passed down, so if you've got two cave people, cavemen, and one of them says, no I'm really not that interested in sex. And one of them says yes I'm extremely interested in sex, and I want to have sex with as many people as possible, which one's going to have more offspring and pass down their preferences? The one who's deeply interested in sex. So evolutionary psychology says men should have evolved over countless generations psychological mechanisms that alert them to sexual availability in partners. They should alert them to, uh, they should have mechanisms that, that make them, highly desirous of sex. And that should alert them to fertility, if possible, or at least availability in their partners. So, for example, of all the people I can have sex with, and again, sex doesn't take a lot of time, but it takes some time, if I have a choice of people to have sex with, from an evolutionary standpoint, I want to make sure I'm having sex with the person who's likely to get pregnant and have my child. So anything associated with fertility, in a partner, I should prefer. Well, what, what kind of things are associated with fertility? It turns out clear skin, youth, health. So if the challenge is to get access, for men, since they don't have to invest much more than that, men should have evolved psychological mechanisms that help them to solve that problem, help them to get access to fertile females. If the challenge for women is to, uh, get protection while they’re gestating this precious single child, they should have evolved psychological mechanisms that help them solve that problem, that alert them to the presence of men who are capable of protecting them and investing in their child. Well, according to evolutionary psychology, that's what happened. And that's what happened 30, or 40,000 years ago and the product was us. And the result is, according to evolutionary psychology, they say, if we're right, then these mechanisms should characterize the human species, and men and women should differ in these ways anywhere that you measure them. Now, well, uh, uh, there's some of you, this is not a noncontroversial idea. And, there, if some of you are finding this controversial that's okay. And we'll get to that in a moment. Uh, but that's a lot of thinking. So far that's all thinking, talking, and thought experiments. So what kind of research would you do? Is there a way to test this theory? There is, and a lot of the research starts, and some of it ends, by predicting and explaining gender differences. Follows directly from the theory of parental investment. The theory of parental investment says since men and women are so differentially invested in the production of offspring, then men and women should have evolved very different psychological mechanisms and especially different preferences for mates and different responses to relationship behavior. So, and this should be true in the human species. Because this sort of evolved before there was Chinese and American, before there was people in Australia and people in Alaska. This should have evolved when we were all just one close, living-together species, so it should still be true since in evolutionary, evolutionary terms, no time has passed. So let's see if it's true. And people like David Buss have done a lot of research saying I think that I can explain male and female gender differences in attraction and in mate selection, and other sort of intimate relationship processes, like, for example, jealousy. One of David Buss' most famous studies asks people a simple question. He started in college students and he gave them a simple question, and I'm going to ask you this question. I'm not asking you to raise, you don't have to announce to answer, just think about it. Here's the question. Which of these is worse for you? Which of these situations would you find most intolerable? One, your mate is emotionally committed to you, but sexually unfaithful. He has sex with someone else, doesn't mean anything though, emotionally, you're it. Or, this other situation, which is, your mate is sexually faithful to you but has an emotional connection with someone else. A crush, or a passionate communication by e-mail or whatever. You see the issue? Which is worse, sexual infidelity or emotional infidelity? Play with that, think about it. Roll it around in your head a little bit. One is, my partner's having, had sex with somebody else but they still love me, versus my partner’s still is having sex just with me but sort of has this thing going on with someone else. There aren't having sex, but they still have this thing, this connection, they're like sharing intimacies over coffee. Which is worse for you? Well, raise your hand if you have an answer, if you really have a strong preference for one or the other. Not, not that many hands up. So some people can't decide. Well, well what Buss did is he forced the question. He said, I force, choose, make a choice dammit. And what he found in college students was very clear. Big difference between genders. Predict the effects, which gender found the emotional infidelity worse?

Students: Women

Benjamin Karney: Correct. And which gender found the sexual infidelity worse, men. And he says that's why, that's perfectly explained by evolutionary theory because, think about it. If you're a woman and you want, you need, you’re a cavewoman living in the cave and you need your male protector to protect you, especially while you're immobile within the, in the, in the longest late stages of pregnancy. So if, now if you discover that your man had sex with somebody else, but is still back with you, taking care of you, giving you all the saber tooth tiger meat when he comes back from the hunt, you're not thrilled by sexual infidelity, don't get me wrong, but at least you’re getting a lot of other things that you need, it could be worse. But on the other hand, if your man is in love someone else, well, he might then, he might give the saber tooth tiger meat to that other person he likes better than you. Now that's going to be worse. He might not take care of your kids, that's going to be worse. So, yeah, the emotional infidelity is more threatening. What if you're a man living in that same cave? For you the big problem is, if I'm giving you and this child my saber tooth tiger meat, it had better be my child. Because evolutionary speaking, the worst thing for me would be to give you all my resources for someone else's kid. That would be terrible, but how can I know whether it's my kid or not? Well, it looks kind of like me, but it looks a little bit like George over there too. Well, if I'm cave guy, here's what I ought to do. I've got to evolve, I've got to have psychological mechanisms alerting me to fidelity. To making sure that you are sexually faithful, because if you’re sexually unfaithful then, and like then you might be having someone else's kid, and that will trick me, and, it would be very bad for me. So men should say sexual infidelity no, no, no. Go have all the crushes you want, but no sexual infidelity. And that's what his college students found. Kind of neat. But here's what, David Buss went further. He went and he asked that same question in 36 countries across the world. In industrialized nations, in moderately industrialized nations, in un, non-industrialized nations, in Amazonian tree people tribes, in Aborigine tribes, in every other kind of situation. And he always got the same results no matter what. He always found, that women were more threatened by emotional infidelity, men were more threatened by sexual infidelity. And he said, look, and this what David Buss says in talks. He says, "Have a proven that this has evolved? No. But, you do a better job. Go ahead, you explain better than I have why men and women all over the planet Earth have this difference. And I don't think you can do it" says David Buss. I don't think you can do it. But I have a theory that explains not just it doesn't just say men and women are different, but explains here's how they're different and why. Now, that's not the only thing he does. He also looks at mate preferences. So for example, let me just ask you, take a guess, pop quiz, don't pull out any paper, we'll just do this orally. Which gender is more likely to be attracted to a partner that's older than themselves? Good guess. Which gender is more likely to, uh, wait, you did say women, right? Which gender is more likely to be attracted to a mate that's shorter than themselves? Men. He says, now, that's obvious, right? You didn't have to guess, but why is it true? It's one thing to say, yeah, men and women are different, but why, why is it true? Explain to me why that should be true. David Buss says evolutionary theory doesn't just describe it, it explains it, it says yes, there's a reason, there's a reason why human beings evolved this way. Because that preference is true all over the planet Earth. You could look at tribal peoples, you could look at industrialized peoples. Men are vastly more likely to be partnered with mates that are younger than themselves and shorter than themselves. And women are vastly more likely to be partnered with mates that are older than themselves and taller than themselves. Because men are looking for youth and fertility, and women are looking for resources and protection. So what we've got, not only do they find these differences but they find them everywhere. Now, here's where I need to make a point, because people can easily misunderstand this. Okay, now maybe you’re thinking well, yeah, that's fine for industrialized nations, or whatever 36 countries, but I am a student at UCLA, and I assure you, that when I look for a mate I am not thinking of that person's reproductive things. Question, Cassie.

Cassie: How does this theory apply to same-sex couples?

Benjamin Karney: Yeah, well, to same-sex couples? Oh, great question. Uh, here's how. Same-sex couples are, uh, by definition, they both are of the same sex. So, now you should have, you should have two people who have comparable preferences. And, so, sometimes, some of the stuff will fall out and not be relevant in same-sex relationships, but some of the stuff, uh, will still be quite relevant. We'll actually be talking about this, I think it's next week, in more detail. But for now let me say that, for example, evolutionary psychology says that men should be much more interested in having sex with multiple partners than women. We just said that a moment ago. Well if that's true, then even in same-sex relationships, uh, same-sex relationships between men should be much more open, uh, or, uh, accepting of extra-relational sexual activity than same-sex relationships between women. And study after study shows that's true. On the other hand, uh, what's interesting about same-sex relationships is that it allows us to tease apart effects, uh, preferences associated with sexual orientation, and preferences associated with gender. And a lot of research has actually tried to do that in really interesting and provocative ways, which we'll talk about next week. But, what I thought you were going to ask me when I first heard your question was, I thought you said, how does this account for safe sex. As opposed to same-sex. Like what about people who, you know, wear condoms or aren't interested in reproduction at all. Who're like, no, here's the last thing I want, reproduction. Well, that's irrelevant, because the point of the theory is not that these are totally, that you’re consciously saying that I want these resources or I want fertility. No, what's conscious is a preference for something. It so happens that that something in our ancestral past was a cue to resources, protection, or fertility. Today it might not be, but that doesn't matter, the preference hasn't changed. And let me say that again because that's like crucial to avoid a deep misunderstanding that many people have about this theory. If, if I am out and about, and I see a potential partner. I'm not saying, hey, fertile. All I'm saying is, hey, clean skin, straight teeth, curvy body, young, that's attractive. Now why is that attractive? Why isn't big, round attractive? Why isn't that attractive? It's attractive, according to evolutionary theory, because in our ancestral past people who had those things were more fertile. Nowadays, it may not be associated with fertility, you may be less fertile maybe, but the preference hasn't changed yet, hasn't caught up. You understand? We didn't evolve a preference for fertility, no, we evolved a preference for cues that, in our ancestral past signaled fertility. Even if those cues don't signal fertility anymore, even if we're not thinking about fertility, the preference for the cues remains. And it does. Even if you're not thinking of fertility, women frequently say, I'm not thinking of fertility, I'm just, just saying, I'm just telling you what I like, it just happens to be big and broad. Which gender's more likely to say I'd like my partner to be broad in the shoulder and big and bulky and burly? Well, men are unlikely to say that. Because there was never a time when those things were cues to things to something that men wanted in our ancestral past. But there were, there was a time when those things were cues to something you'd want. If you're living in a cave, it's very adaptive to have a partner who is big and burly. It may not be adaptive now, now it might be adaptive to have a partner who's sensitive and wears a tie. Unfortunately, for us, that preference remains. Was there a question in the back? Was there a question? Yes? Spencer?

Spencer: unintelligible

Benjamin Karney: No! Spencer asked a good question, does this mean there are no similarities between male and female preferences? Not at all. There are many similarities. Whatever would be a preference that would be adaptive for both genders would be a preference that everyone would've evolved, like the preference for health. Men, neither men nor women, are, you know, attracted to festering sores. Uh, question?

Britney: Well, like, what’s happening now with like the increase in finding skinny women attractive, that’s not necessarily the best thing for reproduction, so is that like, an evolutionary thing or is that like some other thing?

Benjamin Karney: Uh, so, is it Deisha?

Britney: Britney.

Benjamin Karney: Say it again?

Britney: Britney.

Benjamin Karney: Britney. So Britney asks, um, you know, what about what's going on now with attraction to really skinny women, you know, where does that come from? I don't want to get too deeply into it, but the, uh, uh, a pure evolutionary psychologists would say that, uh, to the extent that that has become associated with youth and, uh, that we've learned that that's associated with youth then, uh, we find it attractive because we're so, we're attracted to anything associated with youth. That's why, like, people wearing schoolgirl outfits are supposed to be attractive, because we're attracted to youth. That's not the point. The point is I don't want to get too deeply into it because I still have another theory to talk about in the next 20 minutes. One more question, what's your name?

Micah: Micah.

Benjamin Karney: Micah.

Micah: And, um, how does this theory account for the existence of guys who wear ties?

Benjamin Karney: Ha, ha, ha. I'll tell you why. There is an answer, okay, there's an answer, Micah. Thankfully for us. You want, the answer is, well how does, how is that sensitive guys who wear ties even evolved? Like, how would we ever have reproductive success, given this theory? And the answer is, because there is an evolutionary advantage to having a mate who treats you nicely. And will treat your kid nicely, and is unlikely to stray, is unlikely to be sexually unfaithful, or even emotionally unfaithful. There is an advantage. So under some circumstances, say, in fact the best situation for a woman would be to get genes from someone who's big and burly, but have a sensitive guy at home to take care of you and the kid. So, like, to be mates with a sensitive guy who would be treating you nicely and the kid nicely, but also have affairs with big, burly guys which, by the way, is what happens, not all the time, but occasionally. Awesome. So here's the point. Uh, one more thing, is this all too obvious? Sometimes the people criticizing this theory say, well, come on, I knew that men and women were different, big deal. And then you get the stinky T-shirt studies. And I assure you, if you predicted all the results of all this, you won't predict this. Oh, no. Let me tell you about the stinky T-shirt study, probably my favorite research happening in evolutionary psychology. The idea is this, women are looking for genetically fit partners, right? But women, it doesn't matter all the time. Because women, of course, can have sex any time of the month but they only ovulate at a certain period of the month. And unless they're ovulating, what's happening? What's this all about? Well, let's leave that for now. Um, unless. Wait, I have an idea. There we go. Okay, so unless women are ovulating they, it doesn't matter who they have sex with. They're not going to reproduce. So, evolutionary theory says, check this out. That women should be more sensitive to cues in a potential partner when they're ovulating then when they're not ovulating. Now, a lot of women will say, well, I know that you know, that I, uh, feel different at different times of the month, but a lot of the, the, the, in Western culture, a lot of the focus is on the period of menstruation. They'll say, oh, when I'm menstrual then I feel differently, but the rest of the month, you know, I'm fine. But this theory says the period of ovulation which is much less noticeable should be crucial for changing your preferences, of women, because there's no reason for you to care that much when you're not ovulating, and the stakes are very high when you're ovulating. So women should have evolved a different sensitivity to reproductive fitness in a partner only when they're ovulating. Well, here's a sign of reproductive fitness, physical symmetry. It turns out that people who have good genes, who are healthy, are more symmetric down the, the two sides of their body. They going to have ears the same size, eyes the same height, cheek bones the same, nostrils the same size, and if those things are un, or not symmetric, that's a sign of genetic dissymmetry of, uh, of not being quite as healthy. But, you know what, symmetry's a very hard thing to judge. Scientists study with calipers and things like that. So how, how, how might we get a quick way of sensing people's symmetry, or people's genetic fitness? Well, a set of, a group of researchers thought that maybe scent, which we can easily discern in a person, maybe scent is a cue to genetic fitness, that correlates with physical symmetry which we know is a mark of genetic fitness. So here's what they did. They got men, college men to come to the lab and they measured their symmetry, the length of their arms, the size of their eyes, the length of their ears, the height of their cheekbones, and they got men who ranged, some guys were very symmetric, some guys were not. And they asked these men, they gave each man a clean white T-shirt and a bar of unscented soap. And they tell these men, that, for the next three nights before you go to sleep, shower with this unscented soap, and then go to bed wearing this T-shirt. And wear the same T-shirts three nights in a row. And then when you're done seal it is this plastic bag and bring it back to us. So now they've a stack of stinky T-shirts, of T-shirts that have been worn by these men, some of whom are highly genetically fit, and some of whom are not. Then they brought women into the lab. And they asked these women to stick their noses in those plastic bags and sniff those T-shirts. And after each sniff they were asked to rate the T-shirt on its pleasantness, and appealingness, and sexiness. Now, what they found absolutely proved, uh, supported their hypothesis. What they found is that women who were not ovulating could not sniff the difference between a symmetric man and a non-symmetric man, but women who were ovulating preferred the scent of a symmetric man over the scent of a non-symmetric man. And that, my friends, is not something you would have guessed. Uh, Micah.

Micah: Did they survey women like that one study or did they measure the same women at different times during the month?

Benjamin Karney: It was, uh, one study and it was women who they had, they knew some of these women were ovulating right now, and some of these women weren't ovulating right now.

Micah: But doesn’t that, isn’t that, doesn’t that present the same problem that, um, that using a non-longitudinal study, study to measure correlation, experiences? Because like, it was, in effect, you talked about how longitudinal studies have to be employed when they try to correlate one effect to another, so what if some woman couldn’t detect it when she wasn’t on her period, or when she’s not ovulating, rather, but could not detect it when she was ovulating? What if?

Benjamin Karney: Except here's the thing, is that, presumably the timing, this is actually a quasi-experiment. Because each women were basically randomly given all these different T-shirts and the timing of ovulation is essentially random. So, in fact, for the purpose of this experiment women were randomly assigned to either be ovulating on the random day the study was going on, or not be ovulating on the random day. So there's no reason to expect on average any differences between the women, the women who happen to be ovulating that day or the women who weren't. But there were. Let me move on because there's a whole other theory I need to talk about in the next 10 minutes. Evolutionary perspectives link a wide range of variables. Suddenly the way we behave in intimate relationships is being connected to the way we've evolved as biological creatures. Well, that's phenomenal. But, you know, it does focus more on gender differences than variability within gender, because obviously, you might get the mistaken impression from discussions of evolutionary theory that, oh, women, all women want the same thing, and all men want the same different thing, well that's obviously not true. There's a lot of variability within each gender, a lot. Evolutionary theory doesn't talk about that so much. Evolutionary theory focuses on something very interesting, the extent to which genders are different. But in focusing on that it tends to overlook or leave out differences between men or between women. How you explain that? Evolutionary theory doesn't talk about it so much. And evolutionary theory focuses a lot on mate selection in really interesting ways, but on what happens to relationships once they form? Well, it doesn't get so far. It tends to say well some relationships should be better than others, because these relationships, they're meeting adaptive needs, but, what about a relationship that starts good and goes bad, it doesn't have quite as much to say. It's not silent, but it doesn't have as much to say. And let me move on to another theory, equally interesting, I may spend a lot less time on it, I'm sorry about that, attachment theory. Attachment theory also goes back in time also says the source of our current adult intimate relationships lies in the past. Let's look into the past. But, whereas the evolutionary theory says let's look into our ancestral, evolutionary past, attachment theory says let's look into our personal history. Let's look into the relationships that we all had as infants. And the premise of attachment is that the nature of the bonds that we form with our primary caregivers in infancy shapes the relationships that we have throughout our lives. The guy who said this first was a fellow named John Bowlby. And John Bowlby said look, yes I, John Bowlby was an evolutionary theorist, totally. He believed in evolution, he believed that we all evolved, but when he looked back at, he was looking at monkeys. Our primate ancestors. He said, you know what we have in common with our primate ancestors is that we will not survive if we do not have a relationship with our parents. You know, if you're a fish, and you're born, you don't even have to say hi to your mom and dad, you're just off. But, human beings are helpless when they emerge from the womb. When my son finally emerges, he'll be totally helpless, he'll be dependent on us. So he said it makes sense that human beings would have evolved mechanisms to make sure that parents will stick around and take care of that kid. So he said we will have, we've evolved a system, an attachment system, a system for developing attachments between infants and their parents. Which answers the question, why are babies so cute? Babies have evolved to be cute so that we'll stick around and watch them. Even though it's 2 in the morning, and we're tired and would rather sleep. Why do babies, babies don't have to learn how to cry, they're born learning how to, knowing how to cry. Why is that useful? It's useful because that cry gets attention from the people who are attached to them, so that they will get care. Attachment is necessary for the survival of the species. It does a couple things for the baby. One, is it provides a secure base. If babies are attached to their parents, then it's safe to explore because, you know your parents are going to grab you before you go off the cliff. In fact, one of the classic studies of the secure base is, um, they put babies into a room which had a floor, and then a pit, a deep pit covered with a layer of glass. So when the babies are crawling along, they get to the edge, it looks like a pit. What should they do down there? Now, in fact, it's covered with glass so they could cross over it, and basically walk out over the pit, but it does look a little odd. So what they had, what happens is, babies who are securely attached will use their parent as a source of information. And what happened was this, the babies who liked their moms, will look back and look at mom. And the moms have been instructed, some of them, to smile. And when the moms smile, the babies walk-on right over the pit. That's okay, they put glass over the pit. But, uh, when the moms like going, then the babies shied away like, oh, I learned something from mom. Don't go over pits. Well that's how, you imagine, that how things function, that's how babies learn, and it's adaptive, that we should have evolved a system that connects babies to their caregivers so that they can explore the world and learn about the world. What Bowlby said is, from those interactions, we developed, what he called mental models, mental, ideas about relationships in the world. We develop an expectation for care. We learn, you know, are people going to take care of me, or am I on my own here? That first relationship teaches us the answer to that question. Well, a woman named Mary Ainsworth said, how many kinds of mental, I'd like to know what kinds of mental models there are. So she developed a research paradigm called the strange situation. And the strange situation, was a situation where she got babies and their primary caregivers, in this case it was all moms, to come to the lab, play in a room, and what she had, the strange situation was simply, after the mom and the kid were playing in the room for a while, the kid was like, you know, like 18 months old. A stranger would come in, a research assistant, start talking to the baby, and then the mom would slip out. And through the one-way mirror, the researchers would observe, what would the baby do when they discovered the mom is gone. And then, as soon as, the mom would come right back in, and the question is, what does the baby do when the mom comes back? That's the strange situation. And what they found was three different styles of responses to the situation. Half of the kids demonstrated a pattern of behavior that they called secure attachment, in secure attachment what happened is, the kids were exploring the room, they knew mom was there, they didn't have to stare at mom, but when mom slipped out and they discovered it, they started to cry. Where's Mom? When mom came back, they hugged mom like, oh, Mom thanks, you're back., and then they were fine. Securely attached kids wanted Mom around and were soothed when she returned. But the other two, about 25 percentage each, fell into two other categories. There was this avoidant group, the avoidant group ignored Mom. Didn't notice when she left, didn't care when she returned. In contrast, the anxious/ambivalent group, kind of my favorite because they're so poignant. The anxious/ambivalent group, when they discovered mom was, they, they didn't want to leave Mom, they're reluctant to explore the room in the first place, when Mom finally slips out, they freak out, and when Mom comes back, they're mad at mom for leaving. So, Mary Ainsworth and her students said, maybe there are different styles, different mental models that people develop in infancy that we're going to call different attachment styles, secure, avoidant, and anxious. And these are responses to different kinds of parenting. If your parent is dependable, you know your parent is going to be there, you develop a secure attachment style. If you know your parent's not there, you develop an avoidant attachment style. And if your parent is unreliable, you develop an avoidance/ambivalent attachment style. Well people did this research in kids, it's very interesting, and then two researchers of adults said, well, wait a minute, they went back and read Bowlby, and Bowlby said "Hey, these mental models last your whole life." You use these mental models when you develop new intimate relationships in adulthood. And these, and so, uh, two researchers named Phil Shaver and Cindy Hazan said, well, wait a minute. Then, there should be, we should see commonalities between infant parent attachment and adult attachment. And they started asking people some, some questions, well let me ask you the same questions. In what kind of relationships is it okay to talk baby-talk? Parents and children, people in love. Right, if you hear me talking to someone, "Yeah, oh, yeah, honey, sweetie baby," whom I talking to, my wife or my kid? Maybe both. What kind of relationships, do you find people gazing moonily into each others' eyes? Lovers and parents and kids. Who, who's it comfortable to cuddle with. Your lover and your kid, sometimes at the same time. So the idea is, that there's common, maybe it's the same mechanism. Maybe it's the same evolved system that governs our attachments in infancy and our attachments in adulthood. And if that's true, then these are the styles of infant attachment, they should be the same styles in adult attachment. So, to study that, they put a quiz in the newspaper and it looked like this. They put three paragraphs in the newspaper, and they asked people, circle the one that describes you. Let's read them quickly. First one, I find it relatively easy to get close to others, am comfortable depending on them and having them depend on me. I don't often worry about being abandoned. Who's that? Secure. How many of you is that? Don't, don't raise your hand. But good for you. How about this one? I'm uncomfortable being close to others, I find it difficult to trust them, to allow myself to depend on them, I'm nervous when people get too close, which one is that? Avoidant. We’re talking about adults here, how about this one? I find that others are reluctant to get as close as I would like. I worry my partner doesn't really love me, won't want to stay with me, I want to merge completely with someone, and this desire scares people away. Anxious/ambivalent of course. And what, by the way, I just love anxious/ambivalent. Cause anxious ambivalent is saying "I'm so mad at you for not being perfect. I'm so mad at you for not loving me enough. I wish you loved me more, and I hate you for that." So here's the point, the point is, what they found was, 50%, 25, 25, the same proportions, kind of interesting. I'm going to skip this slide, it's all in the text, I'm going to go right to this, what does attachment theory explain? What does attachment theory explain? Well, attachment theory has been used to explain some very interesting and important things. Hey, where do our standards for intimacy come from? Why do some people want to be really close? Why are some people perfectly comfortable kind of being more solitary, or more distant. Like, some people will say, you know, the problem with this person is that I can't breathe, we don't have any independence. Other people say, no, the problem is this person doesn't want me close enough. What's the difference? This says, these differences arise in childhood. In infancy, when we develop our models of what attachment what, um, uh, intimacy's all about. And why do some people have the same, don't you know people who have the same relationships over and over again? Every time it's the same problem. Why? Well, what Bowlby says is we have these mental models, these attachment styles and we bring them with us. And we end up making the same mistakes over and over again. Let's see, if we can do better on Friday. For now, you're dismissed. Thank you.