(单词翻译:单击)
Everyone is afraid of something.
每个人都害怕一些事情。
Maybe you’re afraid of spiders, or heights, or dogs, or the dark.
也许你怕蜘蛛、怕高、怕狗、怕黑暗。
And traditionally, we've thought that's because you learned to be afraid.
传统上，我们认为这是因为你学会了害怕。
Probably because you had a bad run-in with something at some point.
可能是因为你在某个时候，碰到某件不愉快的事。
But there's a different idea out there that's been getting more attention lately:
但最近，有种不同的观点得到更多的关注：
the idea that fears aren’t just learned...they also can be inherited.
恐惧不仅是后天习得的，它们也可以遗传。
The idea isn’t new.
这并不是新观点。
Almost 150 years ago, Charles Darwin wrote about his toddler’s fear of large zoo animals,
大约150年前，查尔斯·达尔文写过一篇关于他蹒跚学步的孩子，害怕动物园里大型动物的文章，
which had never hurt the kid in his life.
这些动物在孩子的一生中从未伤害过他。
In fact, Darwin noted that many children’s fears have nothing to do with their experiences.
事实上，达尔文指出，许多孩子的恐惧与他们的经历无关。
So instead, he thought they had to be inherited, and that they were most likely related to real dangers in our evolutionary past.
相反，他认为它们是遗传的，而且很可能与我们进化史上真实存在的危险有关。
It sounds like a wild idea.
这个观点听起来挺疯狂。
Like, how do you inherit something as abstract as fear?
比如，你是如何继承恐惧这样抽象的东西的？
But over the last fifty years, researchers have been studying just how much fears have to do with inheritance and genetics.
但在过去50年里，研究人员一直在研究恐惧与遗传和基因学之间有多大关系。
And their results have been kind of surprising.
他们的结果令人惊讶。
In this work, they’ve put a lot of effort into understanding one extreme kind of fear, called a phobia.
在这项研究中，他们花了很多精力去理解一种极端的恐惧，叫做恐惧症。
Phobias are an intense fear of an object or situation.
恐惧症是对某个物体或某种情境产生的强烈恐惧。
And while you might throw around that word colloquially,
你可能会用白话来形容这个词，
psychologists define phobias as a type of anxiety disorder that typically lasts at least six months.
但心理学家把恐惧症界定为一种焦虑症，通常持续至少六个月。
Some common phobias include spiders, getting shots, or public speaking.
一些常见的恐惧症包括对蜘蛛、中弹，或者在公众场合演讲的恐惧。
And sure, for most of us, these are unpleasant things.
当然，对大多数人来说，这些都是不愉快的事情。
But for people with phobias, the fear can be so severe that it interferes with their ability to function.
但是，对于恐惧症患者来说，恐惧感会非常严重，以至于影响他们的正常生活。
Like, a person with a phobia of dogs can have a hard time just walking down the street.
比如，一个患有对狗的恐惧症的人就很难在街上散步。
Phobias aren’t uncommon, either.
恐惧症也并不少见。
It’s estimated that up to 15 percent of people will have one at some point in their life.
据估计，高达15%的人在一生的某个时候会有一种恐惧症。
Until 2002, scientists have generally thought that phobias were learned.
直到2002年，科学家们普遍认为恐惧症是后天习得的。
In other words, people developed them as a reaction to something bad happening.
换言之，人们将其发展为对糟糕事情的一种反应。
But that year, the authors of a literature review proposed that there was another pathway for developing phobias: genetics.
但在那一年，一篇文献综述的作者提出了患上恐惧症的另一种方式，即遗传学。
Like, the idea is you could be afraid of something you’ve never come across in your life…just because someone in your past had a bad experience with it.
比如说，你可能会害怕生活中从未遇到过的东西，而仅仅因为过去认识的某个人曾有过不好的经历。
Which...is a totally bizarre thing to think about.
这真是一件怪诞的事。
To get a sense of how much genes influence fear, scientists have begun looking at identical twins.
为了了解基因在多大程度上影响恐惧，科学家们开始研究同卵双胞胎。
Since identical twins have virtually identical DNA,
由于同卵双胞胎的DNA几乎完全相同，
researchers can figure out how heritable a fear is by comparing how often specific phobias appear in identical twins as opposed to other siblings or offspring.
研究人员可以通过比较同卵双胞胎与其兄弟姐妹或其子女的特定恐惧症出现的频率，找出恐惧的遗传性。
Because even though twins often have lots of similar experiences,
因为即使双胞胎经常有很多相似的经历，
they probably don’t share the types of experiences that cause phobias—like getting bitten by a dog or falling out of a tree.
但他们可能不会分享那些导致恐惧症的经历，比如遭到狗咬或从树上掉下来。
One 1998 study of 659 pairs of identical and fraternal twins in Australia looked at how many had a fear of blood.
1998年，澳大利亚的科学家们对659对同卵双胞胎和异卵双胞胎进行研究，调查有多少人恐惧血液。
The study found that genetics accounted for 71 percent of the variation among those people.
研究发现，遗传因素占71%的变异。
Meaning genetic factors play a pretty big role in determining whether a person has some specific fear.
也就是说，基因因素在决定一个人是否具有某种特定恐惧方面，起着相当大的作用。
A 2016 study also found that fear of dental work was over 30 percent heritable.
2016年的一项研究还发现，对看牙的恐惧，有超过30%是遗传的。
So, if you dread going to the dentist, it really might not be your dentist’s fault.
所以，如果你害怕去看牙医，那真的可能不是牙医的错。
Overall, first-degree relatives of people with phobias are more likely to have similar phobias than people with no family history.
总的来说，恐惧症患者的直系亲属比没有家族史的人，更可能患有类似的恐惧症。
So, it’s pretty clear that phobias are heritable!
很明显，恐惧症是遗传的！
Which is wild.
这真是太疯狂了。
But your chances of actually inheriting one seems to vary depending on the phobia itself.
但你真正遗传上一种恐惧症机会，似乎取决于恐惧症本身。
Some of that likely has to do with differences in evolutionary pressure.
其中一些可能与进化压力的差异有关。
For instance, fear of various animals could have evolved for different reasons.
例如，对各种动物的恐惧可能是由不同的原因演变而来的。
Like, it makes sense that some people have phobias of dogs or animals that could potentially attack them.
像有些人对可能会袭击他们的狗或动物存在恐惧症。
But people have phobias of all kinds of other animals.
但是，人们对其他各种动物都有恐惧症。
For instance, lots of us are grossed out by things like maggots and slugs, which are pretty unlikely to attack humans.
例如，很多人都对蛆虫和蛞蝓等不太可能攻击人类的东西感到厌恶。
These phobias seem to have more to do with disgust, which probably evolved to help humans avoid pathogens.
这些恐惧症似乎更多地与厌恶有关，而厌恶可能是进化来帮助人类避免病原体的。
So, since these fears evolved through different routes, they likely involve different genes—and that may be part of what makes different fears more or less heritable.
由于这些恐惧是通过不同的途径进化而来的，它们可能涉及不同的基因，这可能是不同恐惧或多或少可以遗传的原因之一。
The thing is, it’s hard to figure out exactly which genes are playing a role, since several different parts of the genome are involved.
问题是，很难弄清楚到底是哪些基因在起作用，因为涉及基因组的几个不同部分。
So one approach scientists use is called linkage analysis.
所以，科学家使用的一种叫做连锁分析的方法。
This method looks at genetic data from extended families where a specific phobia pops up over and over again,
这种方法研究的是来自大家庭的基因数据。在这些家庭中，
and it picks out patterns of genes that tend to be inherited together.
一种特定的恐惧症会反复出现，并且能找出倾向于一起遗传的基因模式。
If family members who have the phobia also tend to have certain groups of genes, it’s likely that the gene that causes the phobia is somewhere in there.
如果患有恐惧症的家庭成员也倾向于拥有某些特定基因群，那么导致恐惧症的基因很可能就在那儿。
So far, researchers have made some progress in finding the gene regions related to phobias.
到目前为止，研究人员在寻找与恐惧症相关的基因区域方面取得了一些进展。
But they’re also pretty sure that phobias are related to other anxiety and panic disorders, which makes it tricky to tease things apart.
但他们也很确定，恐惧症与其他焦虑症和恐慌症有关，这使得很难把问题区分开。
After all, when phobias run in a family, anxiety disorders often do, too.
毕竟，当恐惧症发生在一个家庭中时，焦虑症也经常发生。
The good news is, even though we don’t totally understand phobias, we still have pretty good ways of treating them.
好消息是，尽管我们并不完全理解恐惧症，但我们仍然有很好的治疗方法。
People who seek help for phobias often use cognitive behavioral therapy,
治疗恐惧症，通常使用认知行为疗法，
which involves talking through fears and gradually exposing themselves to their phobia.
这种疗法包括通过讨论恐惧，并逐渐与自己的恐惧症接触。
Brain imaging suggests that this kind of therapy disrupts the brain circuits that process fear.
大脑成像显示，这种疗法会破坏大脑处理恐惧的回路。
And it’s usually pretty effective for treating phobias—no matter whether yours has more to do with nature or nurture.
不管你的恐惧症是天性的，还是后天患上的，通常对治疗恐惧症非常有效。
Meanwhile, scientists are still working on understanding these extreme fears.
与此同时，科学家们仍在努力理解这些极端的恐惧。
Some are trying to record phobic people’s symptoms in as much detail as possible,
一些人试图尽可能详细地记录恐惧症患者的症状，
so they can connect more of the dots between genetic differences and specific fears.
以便能够将基因差异和特定恐惧之间的更多点联系起来。
Along the way, they’ll also help us understand how our fears connect us not only to our immediate environment
在这一过程中，它们也将帮助我们理解恐惧是如何将我们不仅与眼前的环境联系在一起，
but also to our ancestors and our past.
而且也与我们的祖先和过去联系在一起。
Thanks for watching this episode of SciShow Psych!
感谢收看本期《心理科学秀》！
And if you have a fear—one you were born with or one you learned—you can watch this video next to find out how science can help you conquer your fears.
如果你天生患有某种恐惧症，或是习得了某种恐惧症，可以看下这个视频，看看如何利用科学帮你战胜恐惧。
