英文
Maybe your DNA made you do it.

Whatever investing mistake you have committed lately, there is probably a gene that is often associated with that behavior. Are you predestined to be the prisoner of your genetic code?

To find out, I recently spent a day at the University of Pittsburgh getting a battery of DNA analyses and brain scans. I consider myself a patient and disciplined investor, so I volunteered as a guinea pig in Ahmad Hariri's imaging genetics lab to learn how my genes and brain activity shape my behavior. The results shocked me.

After I spit into a cup, Dr. Hariri had my DNA analyzed to find out which form I have of five genes that influence the brain circuits that generate decisions about risk and reward over time. His findings: In all five genes, I have a variant, or allele, that is sometimes associated with bad investing decisions.

Consider the FAAH gene. Roughly 25% of people with European ancestry carry the 385A allele of this gene. That tends to damp their brains' fear circuitry and to intensify their brains' reaction to the prospect of making money. I am one of those people.

Or take the DRD2 gene. Some 20% of Caucasians have an allele that can make them respond more intensely to gambles, even when no skill is involved. I have it.

When I had my brain scanned with a functional magnetic resonance imaging, or fMRI, machine, that wasn't a pretty picture either.

While I lay inside the fMRI tube, I viewed a card face down and tried to guess whether it was higher or lower than a five. If I got enough of the guesses right, I was supposed to win $10. Whenever my guess turned out to be right, my ventral striatum -- one of the brain's reward centers -- responded roughly twice as intensely as that of the average person in Dr. Hariri's experiments.

That suggests I may get an even more visceral rush out of making money than other investors do. Dr. Hariri has found that people whose brains respond like mine tend to crave the immediate gratification of a quick profit. 'Controlling this kind of impulsive response to reward,' says Dr. Hariri, 'is crucial to success in many aspects of life' -- like investing, where impatience often lowers returns.

Another test showed that my brain is about 50% more sensitive to fear than that of the typical person Dr. Hariri's lab has tested.

Taken together, my genetic markers and my brain activity seemed like a recipe for investing disaster.

Happily, the lab also ran a test to see how I react to real-world financial decisions. That produced a different picture.

Given the choice, would I rather have a small profit sooner or a larger profit later? Many people hate to wait, choosing as little as $50 today rather than wait a year to get $100. I, meanwhile, was willing to wait a year for $100 rather than take anything less than $90 today. When he saw my results, Dr. Hariri joked that I exhibited 'Zen-like patience.'

The contrast between the raw material of my genes and the final output of my behavior isn't unusual. Perhaps 20% of the variation in risk-taking among individuals is genetically determined; the rest comes from our upbringing, experience, education and training. So, while my genes bias my brain toward spooking easily and trying to make a quick buck, that isn't how I actually behave. I hold investments for years, even decades; I don't panic in bear markets, and bull markets make me uncomfortable.

Those habits, I now understand for the first time, don't come naturally to me. I have been fighting my genes for years, and the reflective parts of my brain have been struggling to rein in my emotions for a lifetime.

Growing up on a farm, with warm parents who knew a great deal about history, may have trained me to evaluate momentary changes in a longer-term context and to think twice before acting on gut feelings. From studying the writings and careers of Benjamin Graham and Warren Buffett, I learned to distrust the crowd and to remember that future returns depend on today's prices.

There is always a tug of war inside each of us between nature and nurture. But during scary times like these, says Dr. Hariri, 'environmental stresses can play a critical role in unmasking any underlying biases determined by your genes.' In other words, bear markets give nature the upper hand. It is now harder than ever to stick to the disciplines that can override your genetic impulses, but it also has never been more important.
中文
或许，是你的遗传密码让你那么做的。

不论你最近在投资方面犯了什么错误，很可能是因为你有某种跟这些行为有关联的基因。你是否注定要成为自身基因密码的奴隶呢？

为揭开这个疑问，最近我在匹兹堡大学花了一天时间，接受了大量DNA分析和大脑扫描。我自认为还算是一名耐心且懂得节制的投资者，因此，我自告奋勇在哈里里(Ahmad Hariri)的基因成像实验室充当人类“小白鼠”，以便了解我的基金和大脑活动对我行为的影响。结果让我大吃一惊。

我在一个杯子里留下唾液样本之后，哈里里就开始进行分析，以便找出影响我大脑中负责风险和回报决策回路的5种基因属何种形态。他的分析结果是：在这5种基因中，我都存在有时与不良投资决策相关联的对位基因。

比如FAAH基因。在欧洲血统的人群中，大约25%的人携带这种基因的385A对位基因。这种基因往往会抑制他们大脑的恐惧回路，加剧大脑对赚钱前景的反应。我就是这些人中的一员。

再看看DRD2基因。大约20%的白种人携带一种会让他们对赌博作出较激烈反应的对位基因，即使他们并不懂赌博技巧。这种基因我也有。

在用功能性核磁共振造影仪(fMRI)对我的大脑进行扫描之后，得出的图像也不是很理想。

当我躺进造影仪的舱里，我看到一张底朝下的卡片，然后我需试着估计它的高度与一张5美元的钞票相比是大还是小。如果猜测正确率足够高的话，我就可以得到10美元。每当我猜对的时候，我的大脑纹状体（这是大脑的反馈中心）的反应强度是哈里里医生对一般人所得试验结果的两倍左右。

这表明，我对赚钱的本能冲动比其他投资者要强很多。哈里里发现，像我这样的人往往渴望立刻赚到钱。哈里里说，“控制这种对回报的冲动反应在生活的很多方面都非常重要”，比如在投资方面，没有耐心常常会降低回报。

另一项测试表明，我的大脑对恐惧的敏感度比接受哈里里试验的一般人要高出50%。

总起来看，我的遗传标志和大脑活动特征似乎生来注定要招来投资灾难。

令我欣慰的是，实验室还就我对现实世界财务决策的反应情况进行了测试。结果却不同。

给我的问题是：是选择早些得到较少的利润，还是晚些得到较多的利润？许多人不喜欢等待，会选择今天就拿到50美元，而不是一年后拿到100美元。我的选择是要么是一年后得到100美元，要么是今天拿到不少于90美元。哈里里看到这个结果后开玩笑说，我简直“像禅宗一样富有耐心”。

我的原始基因与我最终行为之间的反差高得不寻常。每个人的冒险偏好度或许有20%从遗传上说是先天决定的，其他则来源于我们的成长过程、经历、教育和训练。因此，尽管我的基因使得我的大脑容易大惊小怪，而且倾向于迅速赚钱，但我的实际行为却并非如此。我会持有某项投资达数年乃至数十年；我对熊市并不恐慌，牛市却会让我感到不舒服。

现在我终于知道，这些习惯并非我天生就有的。多年来我一直在跟我的基因作斗争。在我的一生中，我大脑的反射功能一直试图控制我的情感。

我从小在农场长大，慈爱的父母对历史很了解，或许他们当年培养了我用长远眼光来看待暂时的变化，不要冲动，三思而行。通过研究格拉罕姆(Benjamin Graham)和巴菲特(Warren Buffett)的著作和经历，我学会了不要盲从他人，并记住未来的回报取决于今天的价格。

在我们每个人的内心，天性和后天教育之间永远在相互较量。但是哈里里说，在目前这样的恐慌时刻，“环境压力可能会在相当程度上让你由基因决定的内在倾向暴露出来”。换句话说，熊市之下本能将占据上风。现在这个时候，坚持让自律控制你的基因冲动比以往任何时候都难，但也比以往任何时候更重要。