字幕列表 影片播放 列印英文字幕 Professor Paul Bloom: So what we're doing today is continuing on the theme of emotions. "Emotions" is a two-part lecture and we're continuing along certain themes. I want to begin by responding to a question which was raised in the last class concerning smiling and nonhuman primates. It was a very good question. The issue was: we know that humans have different sorts of smiles to convey different sorts of information. The question was, "do nonhuman primates, like chimpanzees or gorillas or gibbons, have the same many sorts of smiles?" So, I contacted the world's expert on smiling, who did not return my e-mails. So, I contacted the second world's expert on smiling who told me that the answer is "no," that primate--nonhuman primate smiles actually correspond almost entirely to appeasement smiles. They're "don't hurt me" smiles. They're equivalent to the "coy smile" that we saw on humans. But that nonhuman primates do not use smiles for greetings; there's no equivalent to the "greeting smile" or "Pan Am smile"; nor do they use them as genuine expressions of happiness. There's no equivalent to the "Duchenne smile." That's as far as I know. If the world's expert gets back to me and says something different, I'll keep you posted. Another thing. Going back to the beginning theme of the class, what we started--just to review, we talked about the different functions of emotions. And then we talked about smiling and facial expressions. And then we turned to some--to a nonsocial emotion, the case of fear. And then we shifted to social emotions. And we talked about social emotions towards kin and the special evolutionary reasons that would lead them to evolve. And as we were ending, we were talking about the relationship between an animal and its children, particularly in cases like humans and birds and mammals where there tends to be a close relationship with our children. We invest in quality, not quantity. I might produce very few children in my life. And my evolutionary trick then is to focus very intently on them and make sure they survive. If I were to produce 100 children, I could stand to lose a few, but if I just produce five in my lifetime or two or one, they become very precious to me. And so, the story of the evolution of a species like us involves a long period of dependence and deep, deep bonds between the parent and the child. And that's part of what I talked about, how parents respond to children. And I want to begin this class by giving an illustration from a documentary about parental response to children, but I want to give it in a species that's not us. And here is why. I'll explain why with an analogy. I have a friend of mine who studies the psychology of religion. He studies why people hold religious beliefs. And he tells me that when he's talking to a non specialist, somebody not in the field, he doesn't ever tell them, "Yeah, I'm really interested in why people believe in the Bible or why people light the candles on Sabbath or why people go to church" because these are religions that people around here hold, and if you tell people you study them they'll sort of be puzzled, "why would you want to study something like that" or offended. If you want to talk about the psychology of religion to an audience like this, what you do is you start with the exotic. So, you start by talking about people who put butter on their heads. Dan Sperber talks about a culture where the men put butter on their heads in the summer. And it kind of melts and that's part of--one of the things that they do or--you talk about a culture that believes in spirits or that trees can talk. You say you're studying it and they say, "Oh, that's interesting. I wonder why they believe that?" And you use that as a way to look at more general facts that exist even in our culture. You use the fact that we don't take the exotic for granted as a way to motivate the scientific study of things we do take for granted. And this is, of course, true more generally. This was the point in the William James quote when he talked about things that are natural to us and noticed that some very odd things are equally natural to other species. And it's true, I think, in particular when we talk about things like the love we have for our children. So, one way to look at the love we have for our children scientifically, isn't to look at it head-on, because the love we feel towards our own children feels sacred, it feels special, but look at it in other species. And so, one of the nicest illustrations of this is the Emperor penguin, which was--which--whose childcare and mating practices were dramatized in a wonderful movie called "March of the Penguins." And this is interesting because they had this incredibly elaborate and quite precarious system of generating and taking care of offspring. So, I want to show you a brief clip of the movie to illustrate some parts of this. What they do at the beginning, which is not--which leads up to this, is they take a very long trek from the water to their breeding grounds. Their breeding grounds is--are protected from the wind and they're on a firm piece of ice so they could hold the whole pack. They do the breeding there and it's there that the eggs are created. So, this is where the movie begins at this point. "March of the Penguins" was the second best--second most popular documentary of all time, beaten only by "Fahrenheit 9/11." And people responded to it in different ways, which are informative when we think about the generalizations you could make from animal behavior to human behavior. Some conservative commentators saw this as a celebration of family values, such as love and trust and monogamy. Some liberals, who hate everything that's good and true, [laughter] responded by saying, "Well, yeah, they're monogamous for one breeding season. It's a year. Then they go and find another mate. If you add it up, it's pretty slutty." [laughter] I think more to the point, people were impressed and stunned by the rich and articulate and systematic behavior that these animals were showing. Plainly, they didn't pick it up from television, movies, culture, learning, schooling, and so on. To some extent, this sort of complicated behavior came natural to them. And it's understandable that some proponents of intelligent design, or creationism, pointed to this as an example of how God creates things that are deeply, richly intricate so as to perpetrate the survival of different animals. From a Darwinian standpoint, the Darwinian would agree with the creationist that this couldn't have happened by accident, this is just far too complicated, but would appeal to the--to this as an exquisite example of a biological adaptation, in particular a biological adaptation regarding parental care to children shaped by the fact that children share the parents' genes and so parents will evolve in ways that perpetrate the survival of their children. Then there's the other direction, which is how children respond to parents, how the young ones are wired up to resonate and respond in different ways to the adults around them. And we quickly talked about some different theories of this. And I'll just review what we talked about last class. Babies will develop an attachment to whoever is closest. They'll usually prefer their mothers because their mothers are typically those who are closest to them. They'll prefer her voice, her face, her smell. It used to be thought that there is some sort of magical moment of imprinting that when the baby is born, the baby must see his or her mother and "boom," a connection is made. If the baby doesn't, terrible things will happen with attachment later on. This is silly. There is no reason to believe there's some special moment or special five minutes or special hour. It's just in the fullness of time babies will develop an attachment to the animal that's closest to it. They will recognize it as, at an implicit level, at an unconscious level, as their kin. Well, how does this work? How does the baby's brain develop--come to develop an emotional attachment to that creature? Well, you remember from Skinner that operant conditioning could provide a good answer to this. And this is known as the "Cupboard Theory," which is babies love their moms because their moms provide food. It's the law of effect. It's operant conditioning. They will approach their mothers to get the food from them.