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Not Born Yesterday

Page 8

by Hugo Mercier


  slave through a demonstration of the Pythagorean theorem.

  Socrates doesn’t have to force any conclusion on the slave: once

  each premise is presented in a proper context, the slave can draw

  the appropriate conclusions himself. Socrates only has to or ga-

  nize the steps so that the slave can climb them on his own. In a

  way, the answer has been “given out [by the slave] of his own

  head,”13 and yet the boy would likely never have reached it with-

  out help.

  This illustrates the efficiency of reasoning as a mechanism of

  open vigilance. Reasoning is vigilant because it prompts us to

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  accept challenging conclusions only when the arguments reso-

  nate with our preexisting inferential mechanisms. Like plausibil-

  ity checking, reasoning is essential y foolproof. Typical y, you

  receive arguments when someone wants to convince you of

  something you wouldn’t have accepted other wise.14 If you’re too

  distracted to pay attention to the arguments, you simply won’t

  change your mind. If, even though you’re paying attention, you

  don’t understand the arguments, you won’t change your mind

  either. It’s only if you understand the arguments, evaluating

  them in the pro cess, that you might be convinced.

  Reasoning not only makes us vigilant but also open- minded,

  as it helps us accept conclusions we would never have believed

  without argument. I mentioned previously studies showing that

  people tend to put more weight on their own views than on other

  people’s opinion, moving only about a third of the way toward

  the other on average (the length of the Nile example). When

  people are provided with a chance to discuss the issue together,

  to exchange arguments in support of their views, they become

  much better at discriminating between the opinions they should

  reject and those they should accept— including opinions they

  would never have accepted without arguments.15

  The vast majority of our intuitions are sound— other wise we

  wouldn’t be able to navigate our environment, and we would

  have been selected out a long time ago. Because we recruit these

  intuitions to evaluate the reasons people offer us, the reasons we

  recognize as good enough to warrant changing our minds should,

  more often than not, lead to more accurate opinions and better

  decisions. The exchange of arguments in small discussion groups

  should thus tend to improve per for mance in a variety of tasks,

  as people figure out when to change their minds, and which new

  ideas to adopt. This is exactly what has been observed, as ex-

  changing reasons al ows forecasters to make better predictions,

  w h at t o b e l ie v e ? 55

  doctors to make better diagnoses, jurists to make better judicial

  decisions, scientists to develop better hypotheses, pupils to bet-

  ter understand what they’re taught, and so on.16

  Challenging Arguments

  To make us more open- minded, reasoning should evaluate ar-

  guments as objectively as pos si ble. In par tic u lar, people should

  be able to spot a good argument even if its conclusion is deemed

  implausible. When we’re told that the correct answer to the

  Linda, Paul, and John prob lem is Yes, plausibility checking says

  no (for people who got the prob lem wrong). When your col-

  league suggests taking the bus, which you know to be slower,

  plausibility checking says no. Yet in both cases, once the argu-

  ments have been presented, reasoning does its job, overcoming

  the initial rejection suggested by plausibility checking. But maybe

  you would have been less likely to accept the arguments if you

  had felt more strongly that their conclusion was wrong?

  In an experiment with participants solving the Linda, Paul,

  and John prob lem, we got participants so confident in the wrong

  answer that we had to add some extra options on the confidence

  scale; other wise, they all claimed to be “very confident” they had

  chosen the right answer. Even with the extra options, we ended

  up with many participants saying they were “as confident as in

  the things I’m most confident about” that the wrong answer was

  correct. Yet these ultraconfident participants were just as likely

  to recognize the right argument, when it was provided to them,

  as those who were less confident.17

  Arguments might change people’s minds when they relate to

  riddles. For all their overconfidence, people aren’t particularly

  attached to their (wrong) answers. But what about things that

  matter: our personal life, politics, religion? Are we still able to

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  evaluate arguments objectively then? Three strands of evidence—

  experimental, historical, and introspective— make me hopeful

  that good arguments generally change people’s minds, even when

  they challenge deeply held beliefs.

  In many experiments, participants have been offered argu-

  ments that vary in strength— from the downright fallacious to

  the unimpeachable— and asked to evaluate them. In other stud-

  ies, researchers have mea sured how much the participants

  changed their minds as a function of the quality of the arguments

  they were presented with. The conclusion of these studies is that

  most participants react rationally to arguments, rejecting falla-

  cious arguments outright, being more convinced by strong than

  by weak arguments, and changing their minds accordingly.18

  Historical evidence also suggests that arguments work, even

  when they support conclusions that are quite revolutionary. In

  the early twentieth century, some of the West’s greatest minds—

  such as Bertrand Russel , Alfred North Whitehead, and David

  Hilbert— were attempting to provide a logical foundation for

  mathe matics. In 1930, a young, unknown mathematician named

  Kurt Gödel offered a proof that this could not be done (more

  precisely, that it is impossible to find a complete and consistent

  set of axioms for all of mathe matics).19 As soon as they read the

  proof, every one who mattered accepted it, even if that meant

  jettisoning de cades of work and kissing their dream good- bye.20

  Beyond mathe matics and its perfect demonstrations, good ar-

  guments also work in science, even if they challenge established

  theories. It is simply not true that, as Max Planck complained,

  “a new scientific truth does not triumph by convincing its

  opponents and making them see the light, but rather because

  its opponents eventually die, and a new generation grows up

  that is familiar with it.”21 When the evidence is there, new

  theories are promptly accepted by the scientific community,

  w h at t o b e l ie v e ? 57

  however revolutionary they may be. For example, once suffi-

  cient evidence had been gathered to support plate tectonics, it

  only took a few years to turn it from fringe theory to textbook

  material.22

  Good arguments even work in the po liti cal and moral realm.

  In The Enigma of Reason, Dan Sperber and I reviewed the exam-
<
br />   ples from mathe matics and science just mentioned but also the

  amazing story of British abolitionism, when a nation was per-

  suaded to abandon the slave trade in spite of the economic costs

  involved.23 In many countries, the past de cades have seen dra-

  matic improvements in the rights of women, LGBT+ individu-

  als, and racial minorities. In each of these cases, community

  leaders, intellectuals, journalists, academics, and politicians spent

  time and effort developing arguments drawing on a variety of

  moral and evidential sources. People read and heard these argu-

  ments and appropriated some of them in their everyday con-

  versations.24 Even if good arguments are not the only cause of

  the momentous changes we have witnessed, the efforts spent

  developing, laying out, and communicating good reasons for

  people to change their minds have likely contributed to dramatic

  changes in public opinion.

  On a personal level, I believe we have all experienced, at some

  time or other, the pull of uncomfortable arguments. When I was

  going to university, being a (staunch) leftist was very much taken

  for granted. But I kept encountering arguments that challenged

  some of the po liti cal tenets widely accepted among my peers.

  Ignoring these arguments would have had no negative practical

  consequences for me personally— then as now, I have essentially

  no po liti cal power— and would only have brought social ben-

  efits in the form of approval by my peers. Yet I couldn’t help but

  feel the strength of these alternative arguments. Even if their con-

  clusions remained for some time somewhat disturbing to me,

  58 ch ap t er 4

  they played a significant role in shaping my current po liti cal

  opinions.

  Arguably, it is this power of a wel - thought- out argument that

  led Martin Luther to develop a distaste—to put it mildly— for

  reason, distaste that he expressed quite floridly: “Reason is by

  nature a harmful whore. But she shall not harm me, if only I re-

  sist her. Ah, but she is so comely and glittering. . . . See to it that

  you hold reason in check and do not follow her beautiful cogita-

  tions.”25 In the context of the religious battles he was fighting,

  we can imagine Luther encountering arguments that challenged

  his moral and religious views. Had Luther been able to easily re-

  ject these arguments, had he found no strength in them at al ,

  he surely would not have felt this internal turmoil and developed

  such resentment toward reason.

  What If Our Intuitions Are Wrong?

  When it comes to evaluating the content of communicated in-

  formation, people rely on two main mechanisms: plausibility

  checking, which compares the content of the message with our

  preexisting beliefs, and reasoning, which checks whether argu-

  ments offered in support of the message resonate with our pre-

  existing inferential mechanisms.

  I have made the case that plausibility checking and reasoning

  function well as devices of open vigilance. We can rely on our

  prior beliefs to evaluate what we’re told without falling for a con-

  firmation bias or becoming more polarized because of backfire

  effects. Reasoning evolved to allow a greater degree of open-

  mindedness, as good arguments help people accept conclusions

  they would never have accepted other wise, even conclusions

  that challenge deeply held beliefs.

  w h at t o b e l ie v e ? 59

  The main issue with plausibility checking and reasoning isn’t

  their potential biases in relating communicated information to

  our prior beliefs and inferences but the prior beliefs and infer-

  ences themselves. Our minds evolved so that most of our beliefs

  would be accurate, and most of our inferences sound. Indeed, in

  the wide variety of domains we evolved to deal with— from fig-

  uring out what food to eat to what people mean when they

  speak—we perform wel . We also draw sound inferences in do-

  mains that are evolutionarily novel, if we’ve had a lot of oppor-

  tunities for learning: bil ions of people are now able to read with

  near- perfect fluency; human computers— before they were re-

  placed by electronic versions— could perform complex mental

  calculations with few slipups.

  By contrast, if we attempt to draw inferences in any domain

  that evolution and learning haven’t equipped us to deal with, we

  are likely to be systematically wrong. When tackling novel ques-

  tions, we grope for solutions and reach for some adjacent cogni-

  tive mechanism that appears relevant to the question at hand.

  This adjacent cognitive mechanism might well be the same for

  most of those struggling with the same question. When many

  people get things wrong in the same way, cultural patterns can

  emerge.

  Imagine someone with no access to science wondering why

  animals have traits that are so well adapted to their environment.

  We’re not equipped with mechanisms to answer this question

  directly (why would we? the practical benefits are essentially nil).

  By contrast, recognizing and understanding artifacts matters

  a lot, and we’re likely equipped with cognitive mechanisms to

  deal with that prob lem. Artifacts, in their own way, are also

  adapted to their environment. Because we know that artifacts

  are made by agents, it appears to make sense that adaptive traits

  60 ch ap t er 4

  in animals have also been created by agents.26 This is one of

  the reasons why creationism has a field day, as people find it

  intuitively compelling— certainly more compelling than the

  Darwinian idea that adaptations appear through an unguided

  pro cess of natu ral se lection.

  The same logic applies to many popu lar misconceptions.

  Take vaccination. In the popu lar imagination, it consists in tak-

  ing healthy babies and injecting them with something that con-

  tains a bit of disease (in fact, the agents are typically inert). All

  our intuitions about pathogens and contagion scream folly.27

  The recent rise in anti- vaccination sentiment has often been

  blamed on specific people, master persuaders— from Andrew

  Wakefield in the United Kingdom to Jenny McCarthy in the

  United States— who would have swayed significant swaths of

  the population into harmful, scientifically il iterate be hav ior. In

  fact, the anti- vaccination movement is as old as vaccination.

  Already in 1853, England’s enactment of the first Compulsory

  Vaccination Act “provoked enormous fears of contamination.”28

  After a lull in the early twentieth century— likely due, at least

  in part, to the plainly vis ible success of the polio vaccine— fears

  about vaccination have rebounded in the West. These fears

  create a demand for anti- vaccination rhe toric, demand that is

  rapidly met. As historian of medicine Elena Conis argued,

  “Both the Wakefield study [linking, falsely, vaccines and au-

  tism] and McCarthy’s prominence as a vaccine skeptic [are] the

  products— not the cause—of today’s parent
al vaccine wor-

  ries.”29 The Wakefield study, in par tic u lar, only had an impact

  on the U.S. rate of MMR vaccination (the vaccine that had been

  fraudulently linked to autism) around the year 2000, when it

  was known only by professionals, before it was found to be fake

  and its results contradicted by dozens of other studies. By con-

  trast, the media frenzy that surrounded the vaccines–autism

  w h at t o b e l ie v e ? 61

  link, starting a few years later, had no effect on vaccination

  rates.30

  The examples can be multiplied. We’re not well equipped to

  think about the politics or economics of large, complex, diverse

  states. Instead, we have recourse to intuitions that evolved by

  dealing with small co ali tions in conflict with each other.31 These

  intuitions tell us, for instance, that if someone else benefits too

  much from trading with us, then we must be losing out, or that

  we should be wary of power ful enemy co ali tions colluding

  against us. Hence the popu lar success of protectionist or, more

  generally, antitrade policies, and of conspiracy theories (obvi-

  ously, these intuitions are sometimes right: some trade is bad

  for us, and some people do conspire).

  Not all misconceptions can be neatly explained by the idea

  of misapplied intuitions. The French are big on homeopathy, and

  I’m still stumped as to why— how is duck liver diluted up to the

  point that there’s nothing left of it supposed to cure the flu? In

  chapter 8 I will mention some decidedly nonorthodox beliefs

  shared by the inhabitants of Montaillou in thirteenth- century

  France— that preserved umbilical cords could help win lawsuits,

  for example. They also baffle me (seriously, if you have sugges-

  tions, let me know).

  Stil , compared with, say, creationism, re sis tance to vaccina-

  tion, or conspiracy theories, these odd misconceptions are much

  more culturally specific (the umbilical cord thing in par tic u lar

  hasn’t caught on wel ). Some explanation for their existence is

  certainly required, but the point stands that popu lar miscon-

  ceptions, as a rule, are intuitively compel ing. In the absence of

  strong countervailing forces, it doesn’t take much persuasion to

  turn someone into a creationist anti- vaxxer conspiracy theorist.

  Far from being due to widespread credulity, the prevalence of

  intuitive misconceptions reflects the operation of plausibility

 

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