3月15日下午，贵阳清镇市一名休学在家的19岁大学男生，持刀杀害了一名两岁女童。
经调查，就读于广东某高校的犯罪嫌疑人杨某某因病休学在家。案发当天，杨某某情绪波动较大，其父杨某发现后与其交流谈心，杨某某反映其在校读书期间，与寝室同学、老师、宿管关系较为紧张，学习生活不愉快。
在其父与校方电话沟通过程中，杨某某突然情绪失控，从自家厨房里拿了一把菜刀冲出家门，窜至小区平合处将正在玩耍的被害人刘某某头部砍伤。
Exploring the mind of a killer
探索杀人犯的大脑
I'm a neuroscientist, a professor at the University of California. And over the past 35 years, I've studied behavior on the basis of everything from genes through neurotransmitters, dopamine, things like that, all the way through circuit analysis. So that's what I normally do. But then, for some reason, I got into something else, just recently. And it all grew out of one of my colleagues asking me to analyze a bunch of brains of psychopathic killers.
我是一名神经学家，一名加州大学的教授。在过去的35年里， 我都在研究人的行为。不过研究的基础主要集中在基因，多巴胺之类的神经传导素以及目标分析。这些都是我通常所做的。但出于某种原因，我最近开始迷上了另外的一样东西。究其缘由，则是因为我的一个同事 叫我去研究一批心理变态的杀人犯的大脑。
And so this would be the typical talk I would give. And the question is, "How do you end up with a psychopathic killer?" What I mean by psychopathic killer are these people, these types of people. And so some of the brains that I've studied are people you know about. When I get the brains I don't know what I'm looking at. It's blind experiments. They also gave me normal people and everything.
所以你们这里看到的就是我通常会给的演讲。而我探索的问题就是，“一个人是怎样变成心理变态的杀人凶手的呢？” 我对心理变态的杀手的定义主要是针对这些人，这些种类的人。所以我所研究的一些大脑实际上是属于你们所听说过的人的。当我刚拿到这些大脑的时候，我其实不知道我查看的究竟是何种大脑。算是一个单盲实验，因为他们所给我的大脑中也混杂着正常人的大脑。
So I've looked at about 70 of these. And what came up was a number of pieces of data. So we look at these sorts of things theoretically, on the basis of genetics, and brain damage, and interaction with environment, and exactly how that machine works. So we're interested in exactly where in the brain, and what's the most important part of the brain. So we've been looking at this: the interaction of genes, what's called epigenetic effects, brain damage, and environment, and how these are tied together. And how you end up with a psychopath, and a killer, depends on exactly when the damage occurs. It's really a very precisely timed thing. You get different kinds of psychopaths.
我一共查看了大概70个大脑， 并从中获取了一些数据。我们从理论化的角度出发， 将基因脑损伤、与环境的相互作用， 以及大脑的工作原理作为分析研究的基础。我们所感兴趣的是大脑中的具体位置 和大脑中最重要的部分。所以这就是我们长期以来的研究对象：基因之间的相互作用， 也就是所谓的后生效应， 大脑的损伤，环境因素， 以及他们之间的联系。而一个人变成心理变态狂，变成杀手的原因就决定于脑损伤发生的确切时间。时机的掌握真的需要恰到好处。心理变态狂是有各种各样的。
So we're going along with this. And here's, just to give you the pattern. The pattern is that those people, every one of them I looked at, who was a murderer, and was a serial killer, had damage to their orbital cortex, which is right above the eyes, the orbits, and also the interior part of the temporal lobe. So there is the pattern that every one of them had, but they all were a little different too. They had other sorts of brain damage. A key thing is that the major violence genes, it's called the MAO-A gene.
这就是我们研究的主要方向。而我们所发现的规律就是这些人，我检查过的每一个人， 每一个杀人凶手，每一个连环杀手， 都在大脑的额眶部皮质有所损伤， 就在眼睛、眼眶的正上方。再有就是太阳穴的内侧。所以他们这些人之间是有规律可寻的。但彼此之间有稍微有点不同。他们也有其他类型的脑损伤。重点就在于 最主要的暴力基因 被称作为MAO-A基因。
And there is a variant of this gene that is in the normal population. Some of you have this. And it's sex-linked. It's on the X chromosome. And so in this way you can only get it from your mother. And in fact this is probably why mostly men, boys, are psychopathic killers, or are very aggressive. Because a daughter can get one X from the father, one X from the mother, it's kind of diluted out. But for a son, he can only get the X chromosome from his mother.
正常人群中是有这个基因的变种。你们中的一些人就有这个变种。它是跟性别有关的。是在X染色体上。正因为如此， 你只能从你母亲那里遗传这个基因。事实上，这也许就是为什么男人、男孩更有可能成为心理变态的杀人凶手， 变得非常有暴力倾向。因为女儿还是可以从爸爸那里得到一个X染色体， 从妈妈那里得到另一个，所以总体上的效果就好像被抵消了一样。但如果是个儿子的话， 他就只能从妈妈那里得到一个X染色体。
So this is how it's passed from mother to son. And it has to do with too much brain serotonin during development, which is kind of interesting because serotonin is supposed to make you calm and relaxed. But if you have this gene, in utero your brain is bathed in this, so your whole brain becomes insensitive to serotonin, so it doesn't work later on in life.
这就是它如何从母亲传到儿子的。它也跟成长过程中分泌的血清素有关。这其实是挺有趣的现象， 因为血清素本该让你平静放松下来。但如果你拥有这个基因，在母体里的时候你的大脑就是整个沉浸在血清素之中。所以你的整个大脑都对血清素麻木了。正因此，在你随后的生命中，它就起不到它应有的作用。
And I'd given this one talk in Israel, just this past year. And it does have some consequences. Theoretically what this means is that in order to express this gene, in a violent way, very early on, before puberty, you have to be involved in something that is really traumatic — not a little stress, not being spanked or something, but really seeing violence, or being involved in it, in 3D. Right? That's how the mirror neuron system works.
我之前在以色列给过这个演讲， 就在去年。而这项研究发现确实有着深远的影响。因为从理论上来讲， 若想让这个基因发挥其作用， 引发暴力， 那么在很早的时候，在青春期之前， 你就必须经历一些非常惨痛的事情， 不只是一点小小的压力，不只是被打屁股这么简单， 而是真正目睹暴力， 或者是置身其中。这就是镜像神经元系统的工作原理，对吧？
And so, if you have that gene, and you see a lot of violence in a certain situation, this is the recipe for disaster, absolute disaster. And what I think might happen in these areas of the world, where we have constant violence, you end up having generations of kids that are seeing all this violence. And if I was a young girl, somewhere in a violent area, you know, a 14 year old, and I want to find a mate, I'd find some tough guy, right, to protect me. Well what the problem is this tends to concentrate these genes. And now the boys and the girls get them. So I think after several generations, and here is the idea, we really have a tinderbox.
这样一来，如果你有那个基因， 而又在某个场合下目睹了大量的暴力， 那么灾难就会产生，绝对的灾难。而我觉得在这些长期被暴力笼罩的区域， 很有可能发生的就是 一代又一代的孩子目睹着周边的一切暴力。假如我是一个小女生，生活在某个暴力的地区， 14岁，想找个伴侣， 我当然是会找一个非常强壮的男生，来保护我。这样一来，问题就产生了，因为这些基因被聚集到了一起。他们的儿子和女儿也因此会遗传这些基因。所以我觉得几代过后， 我们真的就有了个引发暴乱的根源。
So that was the idea. But then my mother said to me, "I hear you've been going around talking about psychopathic killers. And you're talking as if you come from a normal family." I said, "What the hell are you talking about?" She then told me about our own family tree. Now she blamed this on my father's side, of course. This was one of these cases, because she has no violence in her background, but my father did.
主要的概念就是这样。但有一天我母亲对我说道：“我听说你到处进行演讲， 讨论心理变态的杀人狂， 听起来你好像来自一个正常家庭一样。” 我说道：“ 你到底在讲什么鬼？” 她随后就告诉了我们自己的家庭史。当然了，她现在是把一切都归咎在我爸爸那边。这算得上是案例之一，因为她的家族史是没有什么暴力倾向的， 但我父亲那边却有。
Well she said, "There is good news and bad news. One of your cousins is Ezra Cornell, founder of Cornell university. But the bad news is that your cousin is also Lizzie Borden.
她说：“我有一个好消息还有一个坏消息。埃兹拉-康奈尔，康奈尔大学的创办者，是你的表兄。
Now I said, "Okay, so what? We have Lizzie."
但坏消息是利兹-伯顿是你的表姐。” 我回答到：“那又怎样呢？利兹是我的亲戚。”
She goes, "No it gets worse, read this book."
她说：“事情比这糟糕。读读这本书。”
And here is this "Killed Strangely," and it's this historical book. And the first murder of a mother by a son was my great-great-great-great-great-great-grandfather. Okay, so that's the first case of matricide. And that book is very interesting. Because it's about witch trials, and how people thought back then.
就是这本书，叫做《离奇谋杀》，是本记录历史的书。里面记载的第一桩谋杀， 是一个儿子杀害母亲的案件， 而犯案者就是我的曾曾曾曾曾祖父。那就是第一起杀母案。这本书其实非常有趣。它讲述了巫女审判， 还有那时候人们的想法。
But it doesn't stop there. There were seven more men, on my father's side, starting then, Cornells, that were all murderers. Okay, now this gives one a little pause. (Laughter) Because my father himself, and my three uncles, in World War II, were all conscientious objectors, all pussycats. But every once in a while, like Lizzie Borden, like three times a century, and we're kind of due. (Laughter)
但它不单单仅此而已。在我父亲那边，还有七位男士， 都是康奈尔家族的人，都是杀人凶手。这就让人不得不倒吸口冷气了。 因为我老爸他自己， 还有我三个叔伯，在二战的时候 都是反战主义者，都是很温和的。但我们家族隔三岔五，就会出现一个像利兹-伯顿这号人物，大概每100年出现三次， 现在差不多该轮到我们这一辈了。
So the moral of the story is: people in glass houses shouldn't throw stones. But more likely is this. (Laughter) And we had to take action. Now our kids found out about it. And they all seemed to be OK. But our grandkids are going to be kind of concerned here. So what we've done is I've started to do PET scans of everybody in the family. (Laughter) We started to do PET scans, EEGs and genetic analysis to see where the bad news is. Now the only person — it turns out one son and one daughter, siblings, didn't get along and their patterns are exactly the same. They have the same brain, and the same EEG. And now they are close as can be. But there's gonna be bad news somewhere. And we don't know where it's going to pop up. So that's my talk. (Laughter)
所以教训就是：居住玻璃屋者不宜以石掷人。但真正的教训是：我不管这个世界对我有多了解，只要我老妈不知道就好。我们家人不得不做点什么。我们的孩子们也是得知了这些情况。他们看上去还不错。但我们的孙子一辈则是需要格外注意的一辈。所以我开始为家里面的每个人做大脑扫描。我们已经开始做脑扫描，脑电图，基因分析， 来查明问题将会出现在哪里。结果唯一有问题的 是一对兄妹，曾经合不来。他们的图象是完全一样。同样的大脑，同样的脑电图。但他们现在却是亲密无间。可是我们知道肯定在某个地方有问题， 只不过我们不确定问题将会出现在哪里。
閱讀更多 英語世界雜誌 的文章
