人为什么容易上当？

思含 黄湘淇

我们好骗，是因为我们太懒。这话可能过于简单化，也过于讽刺。但看看近来流行的“朋友圈”谣言，很多都有悖常识，经不起推敲，但为什么就能横行无忌，还大有野火之势呢？因为我们懒得去辨别来自熟人的信息，即使被辟谣后，还是懒得去改变想法。谣言或许危言耸听，无伤大雅，但却有如流毒，扭曲事实，蛊惑人心，祸患无穷，不得不防。

If you ever need proof of human gullibility， cast your mind back to the attack of the flesh-eating bananas.2 In January 2000， a series of chain emails began reporting that imported bananas were infecting people with “necrotizing fasciitis”—a rare disease in which the skin erupts into livid purple boils before disintegrating and peeling away from muscle and bone.3

According to the email chain， the FDA was trying to cover up the epidemic to avoid panic.4 Faced with the threat， readers were encouraged to spread the word to their friends and family.

The threat was pure nonsense5， of course. But by 28 January， the concern was great enough for the US Centers for Disease Control and Prevention to issue a statement decrying the rumour.6

Did it help？ Did it heck.7 Rather than quelling the rumour， they had only poured fuel on its flames.8 Within weeks， the CDC was hearing from so many distressed9 callers it had to set up a banana hotline. The facts became so distorted10 that people eventually started to quote the CDC as the source of the rumour. Even today， new variants of the myth have occasionally reignited those old fears.11 The banana apocalypse may seem comical in hindsight， but the same cracks in our rational thinking can have serious，12 even dangerous， consequences.

Why do so many false beliefs persist in the face of hard evidence？ And why do attempts to deny them only add grist to the rumour mill13？ Its not a question of intelligence—even Nobel Prize winners have fallen for some bizarre and baseless theories.14 But a series of recent psychological advances may offer some answers， showing how easy it is to construct a rumour that bypasses the brains deception filters.15

One， somewhat humbling， explanation is that we are all “cognitive misers”—to save time and energy， our brains use intuition rather than analysis.16

As a simple example， quickly answer the following questions：

“How many animals of each kind did Moses take on the Ark？”17

“Margaret Thatcher was the president of what country？”18

Between 10% and 50% of study participants presented with these questions fail to notice that it was Noah， not Moses， who built the Ark， and that Margaret Thatcher was the prime minster， not the president—even when they have been explicitly asked to note inaccuracies.19

Known as the “Moses illusion”， this absentmindedness illustrates just how easily we miss the details of a statement， favouring the general gist in place of the specifics.20 Instead， we normally just judge whether it “feels” right or wrong before accepting or rejecting its message.

Based on the research to date， Eryn Newman at the University of Southern California suggests our gut reactions swivel around just five simple questions：21

Does a fact come from a credible22 source？

Do others believe it？

Is there plenty of evidence to support it？

Is it compatible with23 what I believe？

Does it tell a good story？

Crucially， our responses to each of these points can be swayed by frivolous， extraneous details that have nothing to do with the truth.24

Consider the questions of whether others believe a statement or not， and whether the source is credible. We tend to trust people who are familiar to us， meaning that the more we see a talking head， the more we will begrudgingly start to believe what they say.25 “The fact that they arent an expert wont even come into our judgment of the truth，” says Newman. Whats more， we fail to keep count of the number of people supporting a view； when that talking head repeats their idea on endless news programmes， it creates the illusion that the opinion is more popular and pervasive than it really is.26 Again， the result is that we tend to accept it as the truth.

Sticky nuggets27

Then theres the “cognitive fluency” of a statement—essentially， whether it tells a good， coherent story that is simple to imagine.28 “If something feels smooth and easy to process， then our default is to expect things to be true，”29 says Newman. This is particularly true if a myth easily fits with our expectations. “It has to be sticky—a nugget or soundbite that links to what you know， and reaffirms your beliefs，”30 agrees Stephan Lewandowsky at the University of Bristol in the UK.

In light of these discoveries， you can begin to understand why the fear of the flesh-eating bananas was so infectious.31 For one thing， the chain emails were coming from people you inherently32 trust—your friends—increasing the credibility of the claim， and making it appear more popular. The concept itself was vivid and easy to picture—it had high cognitive fluency. If you happened to distrust the FDA and the government， the thought of a cover-up would have fitted neatly33 into your worldview.

That can also help explain why those attempts to correct a myth have backfired so spectacularly， as the CDC found to their cost.34 Lab experiments confirm that offering counter-evidence only strengthens someones conviction.35 “In as little as 30 minutes， you can see a bounce-back effect36 where people are even more likely to believe the statement is true，” says Newman.

Fraying37 beliefs

As a result of these frailties， we are instantly drawn to the juicier details of a story—the original myth—while forgetting the piddling little fact that its been proven false.38 Worse still， by repeating the original myth， the correction will have increased the familiarity of the claim—and as weve seen， familiarity breeds believability.39 Rather than uprooting40 the myth， the well-intentioned correction has only pushed it deeper.

A debunked41 myth may also leave an uncomfortable gap in the mind. Lewandowsky explains that our beliefs are embedded in our “mental models” of the way the world works； each idea is interlinked with our other views.42 Its a little like a tightly bound43 book： once you tear out one page， the others may begin to fray as well. “You end up with a black hole in your mental representation44， and people dont like it.” To avoid that discomfort， we would often rather cling to the myth before our whole belief system starts unravelling.45

Fortunately， there are more effective ways to set people straight and make the truth stick.46 For a start， you should avoid repeating the original story （where possible） and try to come up with a whole alternative to patch up the tear in their mental model.47 For instance， when considering the fears that MMR vaccines may be linked to autism， it would be better to build a narrative around the scientific fraud that gave rise to the fears—rather than the typical “myth-busting” article that unwittingly reinforces the misinformation.48 Whatever story you choose， you need to increase the cognitive fluency with clear language， pictures， and good presentation. And repeating the message， a little but often， will help to keep it fresh in their minds. Soon， it begins to feel as familiar and comfortable as the erroneous49 myth—and the tide of opinion should begin to turn.

At the very least， staying conscious of these flaws in your thinking will help you to identify when you may be being deceived. Its always worth asking whether you have thought carefully about the things you are reading and hearing. Or are you just persuaded by biased50 feelings rather than facts？ Some of your dearest opinions may have no more substance than the great banana hoax of the year 2000.51

1. gullible： 轻信的，易受骗的，下文的gullibility为其名词形式。

2. cast ones mind back： 回顾；flesh-eating： 吃人肉的。

3. 2000年1月，一系列的连环电子邮件开始报道进口香蕉会让人感染坏死性筋膜炎—— 一种罕见的疾病，会让皮肤爆出青紫色的疖子，然后从肌肉和骨头上分离剥落。infect sb. with： 使……感染；necrotizing fasciitis： 坏死性筋膜炎；erupt into：（斑疹等在皮肤上）突然大片出现；boil： 疖子；disintegrate： 分裂，分解；peel away： 剥落。

4. FDA： Food and Drug Administration，（美国）食品药品监督管理局；epidemic： 传染病，流行病。

5. nonsense： 无稽之谈。

6. US Centers for Disease Control and Prevention： 美国疾病控制与预防中心，下文缩写为CDC；issue a statement： 发表声明；decry： 谴责。

7. 起作用了吗？起了才怪！

8. quell： 平息；pour fuel on its flames： 火上浇油。

9. distressed： 忧虑的。

10. distorted： 歪曲的，受到曲解的。

11. variant： 变体；myth： 谣言，谎言；reignite： 重新激起。

12. apocalypse： 启示，大灾难；comical： 滑稽的，好笑的；in hindsight： 事后回想；crack： 裂缝；rational thinking： 理性思维。

13. add grist to the mill： 给磨坊增加制粉用的谷物，这里是比喻给火上浇油。

14. fall for： 信以为真，受骗上当；bizarre： 离奇的，匪夷所思的；baseless： 毫无根据的。

15. 然而近来一系列心理学上的进展或许能提供一些答案，显示出构建一个能绕开大脑“欺骗过滤器”的谣言是多么容易。bypass： 绕开。

16. humbling： 令人感到羞辱的；cognitive： 认知上的； miser： 小气鬼，吝啬鬼；intuition： 直觉。

17. Moses： 摩西，是《圣经》中所记载的公元前13世纪时犹太人的民族领袖；the Ark： 《圣经·创世记》中的方舟，一艘根据上帝的指示建造的大船，目的是为了让诺亚与他的家人，以及世界上的各种陆上生物躲避上帝因故而造的大洪水灾难。

18. Margaret Thatcher： 玛格丽特·撒切尔（1925—2013）， 第49任英国首相。

19. 被问到这些问题时，有10%到50%的参与者没能注意到是诺亚，而不是摩西，建造了方舟，而且玛格丽特·撒切尔是首相，不是总统——即使是在明确要求他们去注意不准确之处时亦如此。explicitly： 明确地；note： 注意；inaccuracy： 不准确的地方。

20. Moses illusion： 摩西错觉，也称“语义错觉”，指听者或读者未能认识到文中的不准确或不连贯之处；absentmindedness： 心不在焉；illustrate： 说明； gist： 主旨，要点；in place of： 代替；specific： 细节。

21. to date： 至今；gut reaction： 直觉反应；swivel around： 围绕。

22. credible： 可信的。

23. compatible with： 与……相符。

24. crucially： 关键是；be swayed by： 被……所左右；frivolous： 无聊的，琐碎的；extraneous： 没有关联的。

25. tend to： 倾向于；talking head： （电视发言者的）头部特写，接受电视采访者；begrudgingly： 勉强地，不情愿地。

26. 此外，我们也没法计算支持某个观点的人数，当接受电视采访者在没完没了的新闻节目上重复他们的观点时，就会制造一种错觉——这个观点比实际上更受欢迎且更为普遍。keep count of： 数……的数目；pervasive： 普遍的，流行的。

27. sticky： 持异议的，抱不合作态度的； nugget： 有价值的信息。

28. cognitive fluency： 认知的流畅性； essentially： 实质上；coherent： 连贯的。

29. smooth： 流畅的；default： 默认设置。

30. soundbite： 简短引述，原话片段； reaffirm： 再肯定，重申。

31. in light of： 根据，鉴于；infectious： 易传播的。

32. inherently： 内在地，固有地。

33. neatly： 严丝合缝地。

34. backfire： 产生出乎意料及事与愿违的结果；spectacularly： 引人注目地；to ones cost： 吃了苦头之后才……，由于付了代价才……。

35. counter-evidence： 反例，反证； conviction： 信念。

36. bounce-back effect： 反弹效应。

37. fraying： 磨损了的。

38. 由于以上人性的弱点，人们总是迅速地为这些绘声绘色的故事情节（即最初的谣言）所吸引，而不去理会其已被证伪的事实。frailty： 弱点；juicier： juicy的比较级，更生动的，更有趣的；piddling： 琐屑的，不重要的。

39. worse still： 更糟糕的是；familiarity： 熟悉；breed： 引起，产生；believability： 可信度。

40. uproot： 根除，连根拔起。

41. debunked： 被揭穿的，被暴露的。

42. be embedded in： 被嵌入在；mental model： 心智模式；be interlinked with： 与……相互关联的。

43. bound： 装订的。

44. mental representation： 心理表征。

45. cling to： 坚持，紧握不放；unravel： 崩溃，瓦解。

46. set sb. straight： 纠正某人的做法；make sth. stick： 让某事持续。

47. alternative： 供替代的选择；patch up the tear： 修补裂缝。

48. 例如，当考虑到那些认定麻疹、腮腺炎和风疹的混合疫苗与自闭症有关的恐慌时，更好的办法是围绕引起恐慌的科学欺骗展开叙事，而不是典型的“辟谣”文章，这反而会在不经意间强化错误信息。MMR vaccines： 麻疹（measles）、腮腺炎（mumps）和风疹（rubella）的混合疫苗；autism： 自闭症；narrative： 叙述，故事；scientific fraud： 科学欺骗；give rise to： 引起；myth-busting： 辟谣的，破除流言的；unwittingly： 不知不觉地，不经意地； reinforce： 强化；misinformation： 误传。

49. erroneous： 错误的，不正确的。

50. biased： 有偏见的。

51. dear： 宝贵的，重视的；substance： 内容，实质； hoax： 骗局，恶作剧。