我是一位腦神經科學家，任教於加州大學教授職，過去 35 年中，我研究行為，基於所有來自基因的神經傳導物質、多巴胺之類的，一路進行到神經迴路分析領域，這是我一般的工作範圍，然而，因為某些因素，最近我也跨足到其他的領域，這全是因為我的同僚請我分析一些精神病殺手的腦袋，所以我一般的談話便會像這樣，提問「你怎會變成一名精神病殺手」？我所指的精神病殺手是這些人，這類的人，有些我研究過的腦袋是你們所熟悉的人物。
當我拿到腦袋時，根本不曉得該從何研究起，這是所謂的盲樣實驗，他們還提供正常人的腦袋等一切，於是，我看過約 70 顆這類的腦袋，結果是一些零碎的資料，我們以理論來處理這類的事情，根據遺傳學、腦袋受損、環境互動及其確切的運作模式，我們感興趣的是腦中的確切位置及腦袋最重要的部份，這便是我們的研究方向。
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.
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. These were blind experiments. They also gave me normal people and everything.
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.
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.
他們的腦袋還有其他的損傷，很關鍵的一點是主要暴力基因的影響，像是 MAO-A 基因，在一般人體內這個基因存在著差異，你們之中有人具備此基因，這和性別有關，因為它存在於 X 染色體，這意謂著你只能從母親的身上獲得此基因，事實上，這可能是為何大部份精神病殺手是男性，或具有非常好鬥的性格，因為女兒可以從父親身上獲一個 X 染色體，再從母親身上獲一個 X 染色體，基因便稀釋掉了，但是兒子卻只能從母親身上獲一個 X 染色體，這解釋了母傳子的現象。
如果我是個年輕女孩，生活在暴亂的地區，成長到 14 歲時，我會想要找個伴，我會想要找個陽剛型的傢伙來保護我，問題是，這樣做只會讓這些基因更加聚集，這樣男孩與女孩們就都具有此類基因了，我想，經數代之後，以這個概念來說，我們培育出了殺手的「導火線」，這就是結論所得出的概念。
They had other sorts of brain damage. A key thing is the effect of the major violence genes, like the MAO-A gene.
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 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.
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.
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.
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 tinder box.So that was the idea.
但我媽之後跟我說：「我聽說最近你一直在講述精神病殺手，而且口吻好像你自己是來自一個正常的家庭」，我回說：「你在說什麼鬼啊」？她接著向我說明我們的家譜，她將責任都歸咎我爸這邊的親人，當然，無可厚非，因為她的背景中並無暴力的記錄，可是我爸這邊卻有，她說：「好壞皆有，你有個堂哥叫Ezra Cornell，他創建了康乃爾大學，但壞的方面，你也有個堂姐叫 Lizzi Borden」，我回說：「好吧，所以呢？我們有個 Lizzi」，她繼續說道：「不，還有更糟的，讀讀這本書」，書名為《Killed Strangely》，就是這本史書描述了第一件子弒母慘案，兇手是我的曾曾曾曾曾曾祖父，這便是有史以來的第一件弒母慘案，這本書很有趣，因為它寫到女巫刑及當時人們的想法。
但故事還沒結束，我父親這邊還有七個或更多人，從康乃爾開始，全是謀殺案的兇手，Okay，這就讓我啞口無言了（笑聲）。因為我父親本人和三位叔叔在二次世界大戰時，都是拒絕服兵役的人，全是溫和人士，但偶爾像 Lizzie Borden這號人物會在一個世紀中出現個三次，就好像是定期謀殺一樣（笑聲），這個故事的寓意是：自身有短，勿擊他人，但情況卻總是這樣（見圖）（笑聲）。
我們必需要採取行動，我們的小孩已經發現了，他們看起來都還好，但是孫字輩就需要擔點心了，於是我便開始做 PET 掃描，對象是家族中的所有成員（笑聲），我們開始做 PET 掃描、EEG 及遺傳分析，看看誰是可疑份子，結果，唯一可疑的是一對同胞兄妹，他們本來不和，但樣本卻呈現出完全相同的基因，他們的腦袋相同，並具相同的 EEG，現在他們很要好，但情況隨時可能改觀，而我們卻不知悲劇何時會爆發，以上是我的演講。
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.
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 Lizzi Borden.
Now I said, "Okay, so what? We have Lizzi."
She goes, "No it gets worse, read this book."
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.
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)
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.