In the last video, I mentioned how group dynamics can involve intragroup dynamics (that is, psychological processes and behaviors taking place within a group) or intergroup dynamics (the same thing between or among different groups). Starting with this video, we'll begin looking at intergroup dynamics that involve categorical judgments of us and them, judgments that can give rise to prejudice and discrimination. Probably the most famous passage ever written by a social psychologist on the topic of prejudice comes from a classic 1954 book by Gordon Allport, entitled The Nature of Prejudice. Allport, who was a professor of psychology at Harvard University for most of his career, wrote, "The human mind must think with the aid of categories... Once formed, categories are the basis for normal prejudgment. We cannot possibly avoid this process. Orderly living depends upon it." What Allport was saying, and later studies have found, is that prejudice and intergroup conflict emerge in part from the natural human tendency to think categorically. Not just categories like table, or chair, or computer, but social categories, like female, or South American, or professor. So, in order to understand prejudice, we first need to understand categorical thinking. And to begin that examination, I want to ask you two very strange questions about this apple. First, would you say that this apple is part of my body? Not a trick question. Let's pause so that you can answer that question. Most people consider an apple and a human body as 100% separate from each other, but let's try an experiment. I'm going to take a bite of this apple, and you pause the video at the exact moment when you think that the bite of apple is no longer a bite of apple— when it's become part of my body. I'll include a timer so that you have an exact time when you pause the video. And once it's paused, please write down the time code that you see here because in just a minute, I'll ask you to enter that into a pop-up question. Then you can just press play and continue watching the video as usual. Okay? You ready? Remember, please pause the video when the bite of apple is no longer a bite of apple— when it's become part of my body. Write down the time code, and please participate—there's no right or wrong answer. What's important is that everyone participates. Okay? Here we go. Oh, that is a good apple—wow! Now, I'm not swallowing anything yet. I'm just chewing, although some of the apple juice just trickled down my throat. I don't know if that matters, but I'm just chewing. Now, most of it is chewed up, and I'm going to swallow half of the bite. Here we go. Half, but I'll keep the rest in my mouth. Oop! Half went down. I'm imagining that some of you have paused the video, but I'm going to continue chewing. And now I'm going to swallow the rest of the bite. Ready? Here we go. Just went down. Oop! No. I think I might have some apple between my teeth. Okay. Now, if you haven't already paused the video and written down a time code, let me give you just another ten seconds to rewind the video and do that before we reach a pop-up question for you to type in your number. Please, everyone participate even if you're not sure what the best answer is. I thought you might like to see how other members of our class answered, so I'll replay the video. But this time I'll show the percentage of students who say that the bite of apple has become part of my body at any given moment— that is, the percentage of students who have paused the video by that point. Oh, that is a good apple—wow! Now, I'm not swallowing anything yet. I'm just chewing, although some of the apple juice just trickled down my throat. I don't know if that matters, but I'm just chewing. Now, most of it is chewed up, and I'm going to swallow half of the bite. Here we go. Half, but I'll keep the rest in my mouth. Oop! Half went down. I'm imagining that some of you have paused the video. But I'm going to continue chewing. And now I'm going to swallow the rest of the bite. Ready? Here we go. Just went down. Oop! No. I think I might have some apple between my teeth. Do you see what's interesting here? It's very hard to say exactly when the apple stops being an apple and starts being me. There's no single answer. Reasonable people can draw the line in different places. Yet even so, society distinguishes between an apple and a person because it's useful to do so. We don't go out into an apple orchard and pick people. We pick apples. The trick is to avoid confusing useful with real. That is, to avoid being fooled into thinking that there's a fixed boundary between an apple and a person, or between any two people, or between people and the environment. After all, rainwater from a thunderstorm in Brazil months ago may have been soaked up by oranges that were made into the orange juice that you drank this past week. And now, that Brazilian rainwater may be circulating in your body. So our connection with the environment is not simply a matter of ashes to ashes and dust to dust in which we'll eventually return to the environment. We're already made up of the environment. Our bodies contain countless molecules that lived as trees and caterpillars, rocks and rainwater. In fact, researchers have found that 90% of the cells in and on the human body aren't even human. They're microbial cells— nonhuman microorganisms that live in our intestines, on our skin, and so forth. The problem is that sometimes we forget that the labels we give things are simply useful linguistic devices, and that these devices are at best, only a rough approximation. So, for example, we talk about ourselves as though we're the same person that our mothers gave birth to, but the reality is somewhat different. The skin on our body is not the same skin that covered us seven years ago. It's made up of entirely new cells. The fat under our skin is not the same fat that was there a year ago. The oldest red blood cell that any of us have came on the scene only 120 days ago or so. And the entire lining of our digestive tract has been replaced in the last three days. Even your skeleton gets replaced every 10 years or so, your muscles every 15, and if you were to average the age of all cells in your body, those of you who are college-aged wouldn't be college-aged. You'd be somewhere around 7 to 10 years old. What endures and is uniquely identifiable isn't any fixed set of atoms or molecules or cells. Those change over time. What endures is simply a pattern—a way of organizing a face, a body, behavior. Likewise, we talk about day and night, plant and animal, female and male, alive and dead, all as though they're separate categories. But this is linguistic. When you look closely, the lines blur, and you can see that they're all really gradients. For instance, we talk about being alive or dead as though they're discrete categories. You're either one or the other. But at what point do people die? When their brainwaves are flat? After their last breath? Their last heartbeat? When the blood in their veins stops moving? Or their reflexes no longer respond? Any definition you come up with will be somewhat arbitrary, like when an apple stops being an apple, because those events all take place at different times. In fact, if you were to define death as taking place when skin cells no longer divide, that time might not come for a day or two after the heart has stopped pumping. So even life and death fall along a continuum. You can be alive in certain respects and dead in others— what you might call "partially dead." But in our language we find it useful to treat life and death as categorically different. When a killer is wanted dead or alive, we understand what's meant. The problem when it comes to social categories is that we sometimes forget that these categories are psychologically and culturally constructed. We stop thinking of Black people and White people or females and males as useful fictions and start regarding them as biological facts. In the United States the biological truth is that millions of White people have genes from Black ancestors. Among White Americans roughly 1 out of every 100 genes comes from a Black ancestor. Conversely, 75 to 90% of Black Americans have White ancestors, including most obviously Barack Obama, whose mother was White and father was Kenyan. On average, Black Americans have gotten one out of every four or five of their genes from a White ancestor. So, if White Americans discriminate against Black Americans, they're usually discriminating against the descendant of a White person. This is the blurry nature of social categories. Now, it might seem obvious that racial lines are blurry, but what about other social categories—are they all that way? The answer is yes. Social categories are, by their very nature, socially constructed. Even categories like "female" and "male" have a fuzzy line and fall along continua. To see why that is, consider the case of transgender people—that is, people whose gender is different than the gender assigned to them at birth or who otherwise don't fit into conventional categories of female or male. I'm not talking about sexual orientation or sexual attraction to others. I'm talking about the perception people have of themselves—of their self-identity and the expression of that identity. So, to take just one example, someone may be born intersexual with genital organs that aren't clearly female or male. There are also cases in which someone's born with XY male chromosomes but is anatomically closer to female, or XX female chromosomes but is anatomically closer to male. In fact, it's possible for someone to be genetically female, anatomically male, hormonally female, but more behaviorally male, and self-identify as neither female nor male. Social categories are complex. To illustrate the point, I'm pleased to share two videos that have been generously made available to our class. The first video is a 9-minute excerpt from "Race: The Power of an Illusion," a documentary that discusses the social and cultural construction of race. Even though the video focuses somewhat on the American case, the general principles apply to all countries. The video was broadcast on PBS, and comes to us courtesy of California Newsreel. The other video is a 23-minute excerpt from an HBO documentary called "Middle Sexes: Redefining He and She," written and directed by Emmy Award winning filmmaker Antony Thomas and narrated by Gore Vidal. In that video the topic is gender identity and intersexuality, including cross-cultural differences in how gender is defined. I'm hoping that these two videos will stimulate some great forum discussions on race and gender that move beyond simple categories of Black, White, Asian, Indian, female, male, and so forth. If you do participate, all I would ask is that you keep a few things in mind. First, please make sure to watch the videos on race and gender before commenting on those topics in the discussion forums. That'll lay the foundation for a much more informed and interesting commentary. Second, many of us have strong views about gender, sexuality, religion, and so forth, so I just want to remind everyone that this is a psychology class—not a place for politicking or religious debate. Third, please respect cultural differences. There's no cultural majority in this class— everyone's a minority, which offers a great chance for cultural exchange, as long as there's respect. Fourth, in a class this size you're bound to have fellow classmates who identify themselves as transgender or intersexual. It's fine to ask them questions or share points of view, but again, please do so respectfully. And finally, if you're someone who has a moral or religious objection to certain gender identities, it's important to understand that people who are born intersex didn't choose to be intersex, any more than someone else chose to be born a particular race, or for that matter, born interracial. In fact, there are undoubtedly people in our class who are intersex without realizing it, simply because they've never been genetically tested, just as most of us have never been tested to see what our racial composition is. Of course, that's not to say that there's anything wrong with social identities that are chosen or that develop later in life. I simply mention these things as a kind of starting point for what I hope will be some very valuable class discussions. Enjoy the videos!