White Paper – Conspiracy Theories

by Cass R. Sunstein & Adrian Vermeule

Harvard Law School / University of Chicago Law School: Law & Economics Research Paper Series; Paper No. 387  http://ssrn.com/abstract=1084585

January 15, 2008


Conspiracy theories are by no means a strictly domestic phenomenon; they can

easily be found all over the world. Among sober-minded Canadians, a September 2006

poll found that 22 percent believe that “the attacks on the United States on September 11,

2001 had nothing to do with Osama Bin Laden and were actually a plot by influential

Americans.”5 In a poll conducted in seven Muslim countries, 78 percent of respondents

said that they do not believe the 9/11 attacks were carried out by Arabs.6 The most

popular account, in these countries, is that 9/11 was the work of the U.S. or Israeli


What causes such theories to arise and spread? Are they important and perhaps

even threatening, or merely trivial and even amusing? What can and should government

do about them? We aim here to sketch some psychological and social mechanisms that

produce, sustain, and spread these theories; to show that some of them are quite important

and should be taken seriously; and to offer suggestions for governmental responses, both

as a matter of policy and as a matter of law.

The academic literature on conspiracy theories is thin, and most of it falls into one

of two classes: (1) work by analytic philosophers, especially in epistemology and the

philosophy of science, that asks what counts as a “conspiracy theory” and whether such

theories are methodologically suspect;8 (2) a smattering of work in sociology and

Freudian psychology on the causes of conspiracy theorizing.9 Both approaches have

proved illuminating, but neither is entirely adequate, the former because the conceptual

questions are both less tractable and less interesting than the social and institutional ones,

the latter because it neglects newer work in social psychology and behavioral economics,

both of which shed light on the causes of conspiracy theorizing. Rather than engaging

with the conceptual debates, we will proceed in an eclectic fashion and mostly from the

ground up, hewing close to real examples and the policy problems they pose.

Our main though far from exclusive focus – our running example – involves

conspiracy theories relating to terrorism, especially theories that arise from and post-date

the 9/11 attacks. These theories exist within the United States and, even more virulently,

in foreign countries, especially Muslim countries. The existence of both domestic and

foreign conspiracy theories, we suggest, is no trivial matter, posing real risks to the

government’s antiterrorism policies, whatever the latter may be. Terrorism-related

theories are thus a crucial testing ground for the significance, causes, and policy

implications of widespread conspiracy theorizing. As we shall see, an understanding of

conspiracy theories has broad implications for the spread of information and beliefs;

many erroneous judgments are a product of the same forces that produce conspiracy

theories, and if we are able to see how to counteract such theories, we will have some

clues about how to correct widespread errors more generally.

Part I explores some definitional issues and lays out some of the mechanisms that

produce conspiracy theories and theorists. We begin by discussing different

understandings of the nature of conspiracy theories and different accounts of the kinds of

errors made by those who hold them. Our primary claim is that conspiracy theories

typically stem not from irrationality or mental illness of any kind but from a “crippled

epistemology,” in the form of a sharply limited number of (relevant) informational

sources. Those who hold conspiracy theories do so because of what they read and hear. In

that sense, acceptance of such theories is not irrational from the standpoint of those who

adhere to them. There is a close connection, we suggest, between our claim on this count

and the empirical association between terrorist behavior and an absence of civil rights

and civil liberties.10 When civil rights and civil liberties are absent, people lack multiple

information sources, and they are more likely to accept conspiracy theories.

Part II discusses government responses and legal issues, in light of the discussion

in Part I. We address several dilemmas of governmental response to conspiracy theories,

such as the question whether it is better to rebut such theories, at the risk of legitimating

them, or to ignore them, at the risk of leaving them unrebutted. Conspiracy theories turn

out to be especially hard to undermine or dislodge; they have a self-sealing quality,

rendering them particularly immune to challenge. We suggest several policy responses

that can dampen the supply of conspiracy theorizing, in part by introducing diverse

viewpoints and new factual assumptions into the hard-core groups that produce such

theories. Our principal claim here involves the potential value of cognitive infiltration of

extremist groups, designed to introduce informational diversity into such groups and to

expose indefensible conspiracy theories as such.

A. Definitional Notes

There has been much discussion of what, exactly, counts as a conspiracy theory,

and about what, if anything, is wrong with those who hold one.11 Of course it would be

valuable to specify necessary and sufficient conditions for such theories, in a way that

would make it possible to make relevant distinctions. We bracket the most difficult

questions here and suggest more intuitively that a conspiracy theory can generally be

counted as such if it is an effort to explain some event or practice by reference to the

machinations of powerful people, who have also managed to conceal their role. This

account seems to capture the essence of the most prominent and influential conspiracy


Consider, for example, the view that the Central Intelligence Agency was

responsible for the assassination of President John F. Kennedy; that doctors deliberately

manufactured the AIDS virus; that the 1996 crash of TWA flight 800 was caused by a

U.S. military missile; that the theory of global warming is a deliberate fraud; that the

Trilateral Commission is responsible for important movements of the international

economy; that Martin Luther King, Jr., was killed by federal agents; that the plane crash

that killed Democrat Paul Wellstone was engineered by Republican politicians; that the

moon landing was staged and never actually occurred.12

Of course some conspiracy theories, under our definition, have turned out to be

true. The Watergate hotel room used by Democratic National Committee was, in fact,

bugged by Republican officials, operating at the behest of the White House.

In the 1950s, the Central Intelligence Agency did, in fact, administer LSD and related drugs under Project MKULTRA, in an effort to investigate the possibility of “mind control.”

Operation Northwoods, a rumored plan by the Department of Defense to simulate acts of

terrorism and to blame them on Cuba, really was proposed by high-level officials (though

the plan never went into effect).13 In 1947, space aliens did, in fact, land in Roswell, New

Mexico, and the government covered it all up. (Well, maybe not.)

Our focus throughout is on false conspiracy theories, not true ones. Our ultimate goal is to explore how public

14 See Edward Glaeser, The Political Economy of Hatred, 120 Q. J. ECON. 45 (2005).

officials might undermine such theories, and as a general rule, true accounts should not

be undermined.

Within the set of false conspiracy theories, we also limit our focus to potentially

harmful theories. Not all false conspiracy theories are harmful; consider the false

conspiracy theory, held by many of the younger members of our society, that a secret

group of elves, working in a remote location under the leadership of the mysterious

“Santa Claus,” make and distribute presents on Christmas Eve. This theory is false, but is

itself instilled through a widespread conspiracy of the powerful – parents – who conceal

their role in the whole affair. (Consider too the Easter Bunny and the Tooth Fairy.) It is

an open question whether most conspiracy theories are equally benign; we will suggest

that some are not benign at all.

Under this account, conspiracy theories are a subset of the large category of false

beliefs, and also of the somewhat smaller category of beliefs that are both false and

harmful. Consider, for example, the beliefs that prolonged exposure to sunlight is actually

healthy and that climate change is neither occurring nor likely to occur. These beliefs are

(in our view) both false and dangerous, but as stated, they do not depend on, or posit, any

kind of conspiracy theory. We shall see that the mechanisms that account for conspiracy

theories overlap with those that account for false and dangerous beliefs of all sorts,

including those that fuel anger and hatred.14 But as we shall also see, conspiracy theories

have some distinctive features, above all because of their self-sealing quality; the very

arguments that give rise to them, and account for their plausibility, make it more difficult

for outsiders to rebut or even to question them.

Conspiracy theories generally attribute extraordinary powers to certain agents – to

plan, to control others, to maintain secrets, and so forth. Those who believe that those

agents have such powers are especially unlikely to give respectful attention to debunkers,

who may, after all, be agents or dupes of those who are responsible for the conspiracy in

the first instance. It is comparatively easier for government to dispel false and dangerous

beliefs that rest, not on a self-sealing conspiracy theory, but on simple misinformation or

on a fragile social consensus. The simplest governmental technique for dispelling false

(and also harmful) beliefs – providing credible public information – does not work, in

any straightforward way, for conspiracy theories. This extra resistance to correction

through simple techniques is what makes conspiracy theories distinctively worrisome.

A further question about conspiracy theories – whether true or false, harmful or

benign – is whether they are justified. Justification and truth are different issues; a true

belief may be unjustified, and a justified belief may be untrue. I may believe, correctly,

that there are fires within the earth’s core, but if I believe that because the god Vulcan

revealed it to me in a dream, my belief is unwarranted. Conversely, the false belief in

Santa Claus is justified, because children generally have good reason to believe what

their parents tell them and follow a sensible heuristic (“if my parents say it, it is probably

true”); when children realize that Santa is the product of a widespread conspiracy among

parents, they have a justified and true belief that a conspiracy has been at work.

Are conspiracy theories generally unjustified? Under what conditions? Here

there are competing accounts and many controversies, in epistemology and analytic

philosophy. We take no final stand on the most difficult questions here, in part because

the relevant accounts need not be seen as mutually exclusive; each accounts for part of

the terrain. However, a brief review of the possible accounts will be useful for our later


Karl Popper famously argued that conspiracy theories overlook the pervasive

unintended consequences of political and social action; they assume that all consequences

must have been intended by someone.15 The basic idea is that many social effects,

including large movements in the economy, occur as a result of the acts and omissions of

many people, none of whom intended to cause those effects.

The Great Depression of the 1930s was not self-consciously engineered by anyone; increases in the unemployment or inflation rate, or in the price of gasoline, may reflect market pressures rather than intentional action.

Nonetheless, there is a pervasive human tendency to think that effects are caused by intentional action, especially by those who stand to benefit (the “cui bono?” maxim), and for this reason conspiracy theories have considerable but unwarranted appeal.16 On one reading of Popper’s account, those who accept conspiracy theories are following a sensible heuristic, to the effect that consequences are intended; that heuristic often works well but it also produces systematic errors, especially in the context of outcomes that are a product of social interactions among numerous people.

Popper captures an important feature of some conspiracy theories. Their appeal lies in the attribution of otherwise inexplicable events to intentional action, and to an unwillingness to accept the possibility that significant adverse consequences may be a product of invisible hand mechanisms (such as market forces or evolutionary pressures) or of simple chance,17 rather than of anyone’s plans.18 A conspiracy theory posits that a social outcome evidences an underlying intentional order, overlooking the possibility that the outcome arises from either spontaneous order or random forces. Popper is picking up on a still more general fact about human psychology, which is that most people do not like to believe that significant events were caused by bad (or good) luck, and much prefer simpler causal stories.19 Note, however, that the domain of Popper’s explanation is quite limited.

Many conspiracy theories, including those involving political assassinations and

the attacks of 9/11, point to events that are indeed the result of intentional action, and the

conspiracy theorists go wrong not by positing intentional actors, but by misidentifying


A broader point is that conspiracy theories overestimate the competence and

discretion of officials and bureaucracies, who are assumed to be able to make and carry

out sophisticated secret plans, despite abundant evidence that in open societies

government action does not usually remain secret for very long.20 Recall that a distinctive

feature of conspiracy theories is that they attribute immense power to the agents of the

conspiracy; the attribution is usually implausible but also makes the theories especially

vulnerable to challenge. Consider all the work that must be done to hide and to cover up

the government’s role in producing a terrorist attack on its own territory, or in arranging

to kill political opponents. In a closed society, secrets are not difficult to keep, and

distrust of official accounts makes a great deal of sense. In such societies, conspiracy

theories are both more likely to be true and harder to show to be false in light of available


But when the press is free, and when checks and balances are in force,

government cannot easily keep its conspiracies hidden for long. These points do not mean

that it is logically impossible, even in free societies, that conspiracy theories are true. But

it does mean that institutional checks make it unlikely, in such societies, that powerful

groups can keep dark secrets for extended periods, at least if those secrets involve

important events with major social salience.

An especially useful account suggests that what makes (unjustified) conspiracy

theories unjustified is that those who accept them must also accept a kind of spreading

distrust of all knowledge-producing institutions, in a way that makes it difficult to believe

anything at all.22

To think, for example, that U.S. government officials destroyed the World Trade Center and then covered their tracks requires an ever-widening conspiracy theory, in which the 9/11 Commission, congressional leaders, the FBI, and the media were either participants in or dupes of the conspiracy.

But anyone who believed that would undercut the grounds for many of their other beliefs, which are warranted only by trust in the knowledge-producing institutions created by government and society.

How many other things must not be believed, if we are not to believe something accepted by

so many diverse actors? There may not be a logical contradiction here, but conspiracy

theorists might well have to question a number of propositions that they seem willing to

take for granted. As Robert Anton Wilson notes of the conspiracy theories advanced by

Holocaust deniers, “a conspiracy that can deceive us about 6,000,000 deaths can deceive

us about anything, and [then] it takes a great leap of faith for Holocaust Revisionists to

believe World War II happened at all, or that Franklin Roosevelt did serve as President

from 1933 to 1945, or that Marilyn Monroe was more ‘real’ than King Kong or Donald


This is not, and is not be intended to be, a general claim that conspiracy theories

are unjustified or unwarranted. Much depends on the background state of knowledge producing

institutions. If those institutions are generally trustworthy, in part because they

are embedded in an open society with a well-functioning marketplace of ideas and free

flow of information, then conspiracy theories will generally (which is not to say always)

be unjustified. On the other hand, individuals in societies with systematically malfunctioning or skewed institutions of knowledge – say, individuals who live in an authoritarian regime lacking a free press – may have good reason to distrust all or most of the official denials they hear. For these individuals, conspiracy theories will more often be warranted, whether or not true.

Likewise, individuals embedded in isolated groups or

small, self-enclosed networks who are exposed only to skewed information will more

often hold conspiracy theories that are justified, relative to their limited informational

environment. Holocaust denials might themselves be considered in this light. When

isolated groups operate within a society that is both wider and more open, their theories

may be unjustified from the standpoint of the wider society but justified from the

standpoint of the group if it maintains its isolation. In these situations, the problem for

the wider society is to breach the informational isolation of the small group or network, a

problem we discuss below.

On our account, a defining feature of conspiracy theories is that they are

extremely resistant to correction, certainly through direct denials or counterspeech by

government officials. Those who accept such theories believe that the agents of the

conspiracy have unusual powers, so that apparently contrary evidence can usually be

shown to be a product of the conspiracy itself.   Conspiracy theories display the

characteristic features of a “degenerating research program”24 in which contrary evidence

is explained away by adding epicycles and resisting falsification of key tenets.25 Some

epistemologists argue that this resistance to falsification is not objectionable if one also

believes that there are conspirators deliberately attempting to plant evidence that would

falsify the conspiracy theory.26 However that may be as a philosophical matter, the selfsealing

quality of conspiracy theories creates serious practical problems for government;

direct attempts to dispel the theory can usually be folded into the theory itself, as just one

more ploy by powerful machinators to cover their tracks. A denial may, for example, be

taken as a confirmation. In this way, conspiracy theories create challenges that are

distinct from those posed by false but dangerous beliefs (recall the belief that prolonged

exposure to sunlight is good for you or that climate change is not occurring).

Accordingly, we will focus on indirect means of undermining such theories, principally

by breaking up the closed informational networks that produce such theories.

So far we have discussed some epistemological features of conspiracy theories, in

the abstract. We now turn to the sociology of conspiracy theorizing, examining the

mechanisms by which such theories arise and expand.

B. How Conspiracy Theories Arise and Spread

1. Crippled epistemologies. Why do people accept conspiracy theories that turn

out to be false and for which the evidence is weak or even nonexistent? It is tempting to

answer in terms of individual pathology.27 Perhaps conspiracy theories are a product of

Another common idea treats conspiracy theories as a form of collective paranoid delusion,

mental illness, such as paranoia or narcissism. And indeed, there can be no doubt that

some people who accept conspiracy theories are mentally ill and subject to delusions.28

But we have seen that in many communities and even nations, such theories are widely

held. It is not plausible to suggest that all or most members of those communities are

afflicted by mental illness. The most important conspiracy theories are hardly limited to

those who suffer from any kind of pathology.

For our purposes, the most useful way to understand the pervasiveness of

conspiracy theories is to examine how people acquire information.29 For most of what

they believe that they know, human beings lack personal or direct information; they must

rely on what other people think. In some domains, people suffer from a “crippled

epistemology,” in the sense that they know very few things, and what they know is


Many extremists fall in this category; their extremism stems not from

irrationality, but from the fact that they have little (relevant) information, and their

extremist views are supported by what little they know.31 Conspiracy theorizing often has

the same feature. Those who believe that Israel was responsible for the attacks of 9/11, or

that the Central Intelligence Agency killed President Kennedy, may well be responding

quite rationally to the informational signals that they receive.

Consider here the suggestive fact that terrorism is more likely to arise in nations

that lack civil rights and civil liberties.32 An evident reason for the connection is that

terrorism is an extreme form of political protest, and when people lack the usual outlets

for registering their protest, they might resort to violence.33 But consider another

possibility: When civil rights and civil liberties are restricted, little information is

available, and what comes from government cannot be trusted. If the trustworthy

information justifies conspiracy theories and extremism, and (therefore?) violence, then

terrorism is more likely to arise.

2. Rumors and speculation. Of course it is necessary to specify how, exactly,

conspiracy theories begin.. Some such theories seem to bubble up spontaneously,

appearing roughly simultaneously in many different social networks; others are initiated

and spread, quite intentionally, by conspiracy entrepreneurs who profit directly or

indirectly from propagating their theories. An example in the latter category is the

34 See W.V. Quine & J.S. Ullian, THE WEB OF BELIEF (2d ed. 1978). On the search for reflective

equilibrium in general, see John Rawls, A THEORY OF JUSTICE (1971).

35 For a classic case study, see Leon Festinger et al., WHEN PROPHECY FAILS (1956). For a general

treatment, see Carol Tavris and Elliot Aronson, MISTAKES WERE MADE (BUT NOT BY ME) (2007).

French author Thierry Meyssan, whose book “9/11: The Big Lie” became a bestseller and

a sensation for its claims that the Pentagon explosion on 9/11 was caused by a missile,

fired as the opening salvo of a coup d’etat by the military-industrial complex, rather than

by American Airlines Flight 77. Some conspiracy entrepreneurs are entirely sincere;

others are interested in money or power, or in achieving some general social goal. Still,

even for conspiracy theories put about by conspiracy entrepreneurs, the key question is

why some theories take hold while many more do not, and vanish into obscurity.

Whenever a bad event has occurred, rumors and speculation are inevitable. Most

people are not able to know, on the basis of personal or direct knowledge, why an

airplane crashed, or why a leader was assassinated, or why a terrorist attack succeeded. In

the aftermath of such an event, numerous speculations will be offered, and some of them

will likely point to some kind of conspiracy. To some people, those speculations will

seem plausible, perhaps because they provide a suitable outlet for outrage and blame,

perhaps because the speculation fits well with other deeply rooted beliefs that they hold.

Terrible events produce outrage, and when people are outraged, they are all the more

likely to attribute those events to intentional action. In addition, antecedent beliefs are a

key to the success or failure of conspiracy theories. Some people would find it impossibly

jarring to think that the CIA was responsible for the assassination of a civil rights leader;

that thought would unsettle too many of their other judgments. Others would find those

other judgments strongly supported, even confirmed, by the suggestion that the CIA was

responsible for such an assassination. Compare the case of terrorist attacks. For most

Americans, a claim that the United States government attacked its own citizens, for some

ancillary purpose, would make it impossible to hold onto a wide range of other

judgments. Clearly this point does not hold for many people in Islamic nations, for whom

it is far from jarring to believe that responsibility lies with the United States (or Israel).

Here, as elsewhere, people attempt to find some kind of equilibrium among their

assortment of beliefs,34 and acceptance or rejection of a conspiracy theory will often

depend on which of the two leads to equilibrium. Some beliefs are also motivated, in the

sense that people are pleased to hold them or displeased to reject them.35 Acceptance (or

for that matter rejection) of a conspiracy theory is frequently motivated in that sense.

Reactions to a claim of conspiracy to assassinate a political leader, or to commit or to

allow some atrocity either domestically or abroad, are often determined by the

motivations of those who hear the claim.

These are points about individual judgments, bracketing social influences. But

after some bad event has occurred, those influences are crucial, for most people will have

little or no direct information about its cause. How many people know, directly or on the

basis of personal investigation, whether Al Qaeda was responsible for the 9/11 attacks, or

whether Lee Harvey Oswald killed President Kennedy on his own, or whether a tragic

death in an apparent airplane accident was truly accidental? Inevitably people must rely

36 For general discussion of the importance of thresholds, see Marc Granovetter, Threshold Models of

Collective Behavior, 83 AM. J. SOC. 1420 (1978).

on the beliefs of other people. Some people will require a great deal of evidence in order

to accept a conspiracy theory; others will require much less. People will therefore have

different “thresholds” for accepting or rejecting such a theory and for acting on the basis

of the theory.36 One way to meet a relevant threshold is to supply direct or indirect

evidence. Another way is simply to show that some, many, or most (trusted) people

accept or reject the theory. These are the appropriate circumstances for social cascades, in

particular informational cascades, whose dynamics help to explain the pervasive

acceptance of conspiracy theories.

3. Conspiracy cascades, 1: the role of information. To see how informational

cascades work, imagine a group of people who are trying to assign responsibility for

some loss of life. Assume that the group members are announcing their views in

sequence. Each member attends, reasonably enough, to the judgments of others.

Andrews is the first to speak. He suggests that the event was caused by a conspiracy of

powerful people. Barnes now knows Andrews’s judgment; she should certainly go along

with Andrew’s account if she agrees independently with him. But if her independent

judgment is otherwise, she would—if she trusts Andrews no more and no less than she

trusts herself—be indifferent about what to do, and she might simply flip a coin.

Now turn to a third person, Charleton. Suppose that both Andrews and Barnes have

endorsed the conspiracy theory, but that Charleton’s own view, based on limited information, suggests that they are probably wrong. In that event, Charleton might well

ignore what he knows and follow Andrews and Barnes. It is likely, after all, that both

Andrews and Barnes had evidence for their conclusion, and unless Charleton thinks that

his own information is better than theirs, he should follow their lead. If he does,

Charleton is in a cascade. Of course Charleton will resist if he has sufficient grounds to

think that Andrews and Barnes are being foolish. But if he lacks those grounds, he is

likely to go along with them.

Now suppose that Charleton is speaking in response to what Andrews and Barnes

did, not on the basis of his own information, and also that later people know what

Andrews, Barnes, and Charleton said. On reasonable assumptions, they will reach the

same conclusion regardless of their private information (which, we are supposing, is

relevant but inconclusive). This will happen even if Andrews initially speculated in a

way that does not fit the facts. That initial speculation, in this example, can start a process

by which a number of people are led to participate in a cascade, accepting a conspiracy

theory whose factual foundations are fragile.

Of course the example is highly stylized and in that sense unrealistic; conspiracy

cascades arise through more complex processes, in which diverse thresholds are

important. In a standard pattern, the conspiracy theory is initially accepted by people with

low thresholds for its acceptance. Sometimes the informational pressure builds, to the

point where many people, with somewhat higher thresholds, begin to accept the theory

too. As a real-world example of a conspiracy cascade, consider the existence of certain

37 See Fabio Lorenzi-Cioldi & Alain Clémence, Group Processes and the Construction of Social

Representations, in GROUP PROCESSES, at 311, 315–17 (Michael A. Hogg & R. Scott Tindale eds., 2001).

38 See Punctuated Equilibrium and the Dynamics of U.S. Environmental Policy (Robert Repetto ed. 2006);

Timur Kuran and Cass R. Sunstein, Availability Cascades and Risk Regulation, 51 STAN. L. REV. 683


judgments about the origins and causes of AIDS, with some groups believing,

implausibly, that the virus was produced in government laboratories.37 These and other

views about AIDS are a product of social interactions and in particular of cascade effects.

4. Conspiracy cascades, 2: the role of reputation. Conspiracy theories do not take

hold only because of information. Sometimes people profess belief in a conspiracy

theory, or at least suppress their doubts, because they seek to curry favor. Reputational

pressures help account for conspiracy theories, and they feed conspiracy cascades.

In a reputational cascade, people think that they know what is right, or what is likely

to be right, but they nonetheless go along with the crowd in order to maintain the good

opinion of others. Suppose that Albert suggests that the Central Intelligence Agency was

responsible for the assassination of President Kennedy, and that Barbara concurs with

Albert, not because she actually thinks that Albert is right, but because she does not wish

to seem, to Albert, to be some kind of dupe. If Albert and Barbara say that the CIA was

responsible for the assassination of President Kennedy, Cynthia might not contradict

them publicly and might even appear to share their judgment — not because she believes

that judgment to be correct, but because she does not want to face their hostility or lose

their good opinion. It should be easy to see how this process might generate a cascade.

Once Albert, Barbara, and Cynthia offer a united front on the issue, their friend David

might be reluctant to contradict them even if he thinks that they are wrong. The

apparently shared view of Albert, Barbara, and Cynthia carry information; that view

might be right. But even if David has reason to believe that they are wrong, he might not

want to take them on publicly. His own silence will help build the informational and

reputational pressure on those who follow.

5. Conspiracy cascades, 3: the role of availability. Informational and reputational

cascades can occur without any particular triggering event. But a distinctive kind of

cascade arises when such an event is highly salient or cognitively “available.” In the

context of many risks, such as those associated with terrorism, nuclear power, and

abandoned hazardous waste dumps, a particular event initiates a cascade, and it stands as

a trigger or a symbol justifying public concern, whether or not that concern is

warranted.38 Availability cascades occur through the interaction between a salient event

and social influences, both informational and reputational. Often political actors, both

self-interested and altruistic, work hard to produce such cascades.

Conspiracy theories are often driven through the same mechanisms. A particular

event becomes available, and conspiracy theories are invoked both in explaining it and

using it as a symbol for broader social forces, casting doubt on accepted wisdom in many

domains. Within certain nations and groups, the claim that the United States or Israel was

responsible for the attacks of 9/11 fits well within a general narrative about who is the


40 See id. at 204.

41 Id. at 223–24.

42 See id. at 212–22, 226–45; Robert S. Baron & Norbert L. Kerr, GROUP PROCESS, GROUP DECISION,

GROUP ACTION (2d ed. 2001), at 540.

43 See Cass R. Sunstein, WHY SOCIETIES NEED DISSENT (2003).

aggressor, and the liar, in a series of disputes – and the view that Al Qaeda was

responsible raises questions about that same narrative. Conspiracy theories are frequently

a product of availability cascades.

6. Group polarization. There are clear links between cascades and the wellestablished

phenomenon of group polarization, by which members of a deliberating

group typically end up in a more extreme position in line with their tendencies before

deliberation began.39 Group polarization has been found in hundreds of studies involving

over a dozen countries.40 Belief in conspiracy theories is often fueled by group


Consider, as the clearest example, the finding that those who disapprove of the

United States, and are suspicious of its intentions, will increase their disapproval and

suspicion if they exchange points of view. There is specific evidence of this phenomenon among citizens of France: With respect to foreign aid, they trust the United States a great deal less, and suspect its intentions a great deal more, after they talk with one another.41 It should be easy to see how similar effects could occur for conspiracy theories. Those who tend to think that Israel was responsible for the attacks of 9/11, and who speak with one another, will end up with a greater commitment to that belief.

Group polarization occurs for reasons that parallel the mechanisms that produce

cascades.42 Informational influences play a large role. In any group with some initial

inclination, the views of most people in the group will inevitably be skewed in the

direction of that inclination. As a result of hearing the various arguments, social

interactions will lead people toward a more extreme point in line with what group

members initially believed. Reputational factors matter as well. People usually want to be perceived favorably by other group members. Once they hear what others believe, some will adjust their positions at least slightly in the direction of the dominant position.

For purposes of understanding the spread of conspiracy theories, it is especially important to note that group polarization is particularly likely, and particularly pronounced, when people have a shared sense of identity and are connected by bonds of solidarity.43

These are circumstances in which arguments by outsiders, unconnected with the group, will lack much credibility, and fail to have much of an effect in reducing polarization. As we will explore below, these circumstances imply that direct government rebuttals of the reigning conspiracy theory will prove ineffective; government will instead do best by using various tactics of cognitive infiltration to break up the polarized information cluster from within.

7. Selection effects. A crippled epistemology can arise not only from informational

and reputational dynamics within a given group, but also from self-selection of members

44 Hardin, supra note 30, at 9-12.

45 Id. at 10.

46 Id. at 11; Hofstadter, supra note 27.

47 Roderick M. Kramer, The Sinister Attribution Error: Paranoid Cognition and Collective Distrust in

Organizations, 18 MOTIVATION & EMOTION 199, 199-230 (1994).

48 Id.

into and out of groups with extreme views.44 Once polarization occurs or cascades arise,

and the group’s median view begins to move in a certain direction, doubters and halfwaybelievers will tend to depart while intense believers remain. The overall size of the group may shrink, but the group may also pick up new believers who are even more committed,

and in any event the remaining members will, by self-selection, display more fanaticism.

Group members may engage in a kind of double-think, segregating themselves, in a

physical or informational sense, in order to protect their beliefs from challenge by

outsiders.45 Even if the rank and file cannot coherently do this, group leaders may

enforce segregation in order to insulate the rank and file from information or arguments

that would undermine the leaders’ hold on the group.

Members of informationally and socially isolated groups tend to display a kind of

paranoid cognition 46 and become increasingly distrustful or suspicious of the motives of others or of the larger society, falling into a “sinister attribution error.”47 This error

occurs when people feel that they are under pervasive scrutiny, and hence they attribute

personalistic motives to outsiders and overestimate the amount of attention they receive.

Benign actions that happen to disadvantage the group are taken as purposeful plots,

intended to harm.48

Although these conditions resemble individual-level pathologies, they arise from the social and informational structure of the group, especially those operating in enclosed or closely knit networks, and are not usefully understood as a form of mental illness. The social etiology of such conditions suggests that the appropriate remedy is not individual treatment, but the introduction of cognitive, informational, and social diversity into the isolated networks that supply extremist theories. We take up the resulting policy problems in the next Part.

II. Governmental Responses

What can government do about conspiracy theories? Among the things it can do,

what should it do? We can readily imagine a series of possible responses.

(1) Government might ban conspiracy theorizing.

(2) Government might impose some kind

of tax, financial or otherwise, on those who disseminate such theories.

(3) Government might itself engage in counterspeech, marshaling arguments to discredit conspiracy theories.

(4) Government might formally hire credible private parties to engage in


(5) Government might engage in informal communication with such

parties, encouraging them to help. Each instrument has a distinctive set of potential

effects, or costs and benefits, and each will have a place under imaginable conditions.

However, our main policy idea is that government should engage in cognitive infiltration of the groups that produce conspiracy theories, which involves a mix of (3), (4) and (5).

If one believes that conspiracy theories are in some sense inconsequential, the

best answer will be for government to ignore them. If children believe in Santa Claus or

the Easter Bunny, there is no problem for government to solve; and the belief that the

49 On those benefits in general, see Scott Page, THE DIFFERENCE (2006).

government covered up the landing of space aliens in Roswell does not seem to be

causing discernible harm, with the possible exception of bad television shows. (This does

not imply that government should ignore conspiracy theories only if they are

inconsequential. As we will see, under certain conditions government may do best to

ignore conspiracy theories and theorists even if it justifiably fears that they will have

harmful effects, because government action may make things worse.) In Section A,

however, we give some reasons to think that some conspiracy theories are consequential


In Section B, we address several dilemmas of governmental response to

conspiracy theories and theorists. Is it best to ignore them, creating a risk that the theory

will spread unrebutted, or to address them, with the risk that addressing the theory will

legitimate and even be taken to confirm it? Assuming budget constraints and limited

resources, should government efforts focus on debiasing the conspiracy theorists

themselves, or solely on preventing the spread of conspiracy theories among the larger

population? How can government get behind or around the distinctive feature of

conspiracy theories — their self-sealing quality, which tends to fold government’s denials

into the theory itself as further evidence of the conspiracy?

An obvious answer is to maintain an open society, in which those who are

tempted to subscribe to conspiracy theories do not distrust all knowledge-creating

institutions, and are exposed to corrections. But we have seen that even in open societies,

conspiracy theories have some traction; and open societies have a strong interest in

debunking such theories when they arise, and threaten to cause harm, in closed societies.

Here we suggest two concrete ideas for government officials attempting to fashion a

response to such theories.

First, responding to more rather than fewer conspiracy theories has a kind of synergy benefit: it reduces the legitimating effect of responding to any one of them, because it dilutes the contrast with unrebutted theories.

Second, we suggest a distinctive tactic for breaking up the hard core of extremists who supply conspiracy theories: cognitive infiltration of extremist groups, whereby government agents or their allies (acting either virtually or in real space, and either openly or anonymously) will

undermine the crippled epistemology of those who subscribe to such theories. They do so

by planting doubts about the theories and stylized facts that circulate within such groups,

thereby introducing beneficial cognitive diversity.49

In Section C, we examine the role of law and judges in fashioning the

government’s response. We will ask whether judges do more good than harm by

invoking statutes such as the Freedom of Information Act to force government to disclose

facts that would rebut conspiracy theories. Our conclusions are generally skeptical: there

is little reason to believe that judges can improve on administrative choices in these

situations. Section D concludes with some brief notes on government efforts to dispel

conspiracy theories held by foreign audiences, especially in Muslim countries.

Throughout, we assume a well-motivated government that aims to eliminate

conspiracy theories, or draw their poison, if and only if social welfare is improved by

doing so. (We do not offer a particular account of social welfare, taking the term instead

as a placeholder for the right account.) This is a standard assumption in policy analysis,

50 See Scott Macleod, Suspicious Minds; In the Arab World, Conspiracy Theories and Rising Anti-Semitism

Deflect Attention From Real Problems, TIME, June 17, 2002, at 28.

51 See, e.g., Frank Rich, Editorial, Dishonest, Reprehensible, Corrupt, N.Y. TIMES, Nov. 27, 2005, at 11

(“Nonetheless Mr. Bush and Mr. Cheney repeatedly pounded in an implicit (and at times specific) link

between Saddam and Al Qaeda until Americans even started to believe that the 9/11 attacks had been

carried out by Iraqis.”).

52 See Clarke, supra note 24, at 91 (noting that “few [conspiracy theories] are actually harmful”).



54 Richard Cohen, Editorial, The Making of a Conspiracy Theory, WASH. POST, Dec. 23, 2003, at A21; see

also Andrea Stone, In Poll, Islamic World Says Arabs Not Involved in 9/11, USA TODAY, Feb. 27, 2002, at


and is useful for clarifying the policy questions, but we note that real-world governments

can instead be purveyors of conspiracy theories. In Egypt, newspapers effectively

controlled by the governing regime regularly spread conspiracy theories about Jews.50

Some believe that the Bush administration deliberately spread a kind of false and

unwarranted conspiracy theory – that Saddam Hussein conspired with Al Qaeda to

support the 9/11 attacks.51 Suppose for discussion’s sake that this is so; then a future

administration motivated to improve social welfare would need to consider whether this

theory is false and harmful, and if it is what can and should be done about it. But this

would just be another case of a conspiracy theory circulating in the population, which

might or might not be worth responding to, in light of the considerations we adduce

below. Nothing of theoretical interest follows from this case for the questions we address

here, which strictly involve optimal responses to conspiracy theories on the part of a (real

or imagined) well-motivated government.

A. Are Conspiracy Theories Consequential?

One line of thinking denies that conspiracy theories matter.52 There are several

possible reasons to think so. First, conspiracy theories may be held by only a tiny

fraction of the population. Perhaps only a handful of kooks believe that U.S. government

officials had any kind of role in the events of 9/11. Second, even if a particular

conspiracy theory is widely held in the sense that many people will confess to it when

polled, conspiracy theories may typically be held as “quasi-beliefs” – beliefs that are not

costly and possibly even fun to hold, like a belief in aliens in Roswell or UFOs, and that

do not form a premise for action.53 Many people profess to believe, and in some sense do

believe, that eternal life depends upon actions that they do not take. So too, perhaps

many people quasi-believe in conspiracy theories yet do not take action on account of

those quasi-beliefs.

In both cases everything depends, of course, on which conspiracy theory and

which population one is discussing. However, as discussed in Part I, there is ample

evidence that some conspiracy theories are not at all confined to small segments of the

population. Overseas, “a 2002 Gallup Poll conducted in nine Islamic countries found that

61 percent of those surveyed thought that Muslims had nothing to do with the attacks of

Sept. 11, 2001.”54 According to an anonymous State Department official in charge of

anti-disinformation, “a great deal of harm can result ‘when people believe these lies and

55 William Weir, Damage Control; State Department Officer Works To Dispel Lies, Conspiracy Theories

and Urban Legends That Harm U.S. Image, HARTFORD COURANT, Oct. 16, 2006, at D1.

56 James D. Fearon, Catastrophic Terrorism and Civil Liberties (unpublished draft), available at


57 See Cass R. Sunstein, WORST-CASE SCENARIOS (2007).

then act on the basis of their mistaken beliefs.’” For example, “Al-Qaeda members ‘were

encouraged to join the jihad at least in part because of disinformation.’”55

The point about quasi-beliefs suggests that many do not in fact take any action on

the basis of their mistaken beliefs. However, this does not at all entail that conspiracy

theories are inconsequential. Even if only a small fraction of adherents to a particular

conspiracy theory act on the basis of their beliefs, that small fraction may be enough to

cause serious harms. Consider the Oklahoma City bombing, whose perpetrators shared a

complex of conspiratorial beliefs about the federal government. Many who shared their

beliefs did not act on them, but a few actors did, with terrifying consequences. James

Fearon and others argue that technological change has driven down the costs of

delivering attacks with weapons of mass destruction, to the point where even a small

group can pose a significant threat.56 If so, and if only a tiny fraction of believers act on

their beliefs, then as the total population with conspiratorial beliefs grows, it becomes

nearly inevitable that action will ensue.

In cases of this sort, the conspiracy theory itself supports affirmatively violent

action on the part of its believers (which only a small fraction will actually take);

conspiracy theorizing leads to an actual conspiracy. Within a network whose members

believe that the federal government, say, is a hostile and morally repellent organization

that is taking over the country, akin to a foreign invader, armed resistance will seem a

sensible course to at least some fraction of the believers. In other, perhaps more

common, cases the conspiracy theory will be of a different nature and will not directly

indicate such action. However, such theories can still have pernicious effects from the

government’s point of view, either by inducing unjustifiably widespread public

skepticism about the government’s assertions, or by dampening public mobilization and

participation in government-led efforts, or both. The widespread belief that U.S. officials

knowingly allowed 9/11 to happen or even brought it about may have hampered the

government’s efforts to mobilize social resources and political support for measures

against future terrorist attacks.

In the nature of things it is hard to find evidence for, or against, such possibilities;

yet it hardly seems sensible to say that because such evidence is lacking, government

should do nothing about a potentially harmful conspiracy theory. That precept would be

paralyzing, because there are uncertain harms on all sides of the question, and because –

as in the case of the Oklahoma City bombing – some of those harms may approach the


B. Dilemmas and Responses

Imagine a government facing a population in which a particular conspiracy theory

is becoming widespread. We will identify two basic dilemmas that recur, and consider

how government should respond. The first dilemma is whether to ignore or rebut the

theory; the second is whether to address the supply side of conspiracy theorizing by

58 For relevant discussion, see Glaeser, The Political Economy of Hatred, supra note.

59 See Timur Kuran, PRIVATE TRUTHS, PUBLIC LIES (1998).

attempting to debias or disable its purveyors, to address the demand side by attempting to

immunize third-party audiences from the theory’s effects, or to do both (if resource

constraints permit).

In both cases, the underlying structure of the problem is that conspiracy theorizing

is a multi-party game. Government is faced with suppliers of conspiracy theories, and

might aim at least in part to persuade, debias, or silence those suppliers. However, those

two players are competing for the hearts and minds of third parties, especially the mass

audience of the uncommitted.58

Expanding the cast further, one may see the game as involving four players: government officials, conspiracy theorists, mass audiences, and independent experts – such as mainstream scientists or the editors of Popular Mechanics – whom government attempts to enlist to give credibility to its rebuttal efforts. The discussion that follows generally assumes the three-party structure, but we will refer to the four-party structure when relevant.

1. Ignore or rebut?

The first dilemma is that either ignoring or rebutting a conspiracy theory has

distinctive costs. Ignoring the theory allows its proponents to draw ominous inferences

from the government’s silence. If the theory stands unrebutted, one possibility is that it is

too ludicrous to need rebuttal, but another is that the government cannot offer relevant

evidence to the contrary; the suppliers of the conspiracy theories will propose the second

inference. On this view, all misinformation (the initial conspiracy theory) should be met

with countermisinformation.

On the other hand, to rebut the theory may be to legitimate it, moving the theory

from the zone of claims too ludicrous to be discussed to the zone of claims that, whether

or not true, are in some sense worth discussing. This legitimating effect can arise in one

of two ways. First, third-party audiences may infer from the government’s rebuttal

efforts that the government estimates the conspiracy theory to be plausible, and fears that

the third parties will themselves be persuaded. Second, some members of the audience

may infer that many other members of the audience must believe the theory, or

government would not be taking the trouble to rebut it. Consider circumstances of

“pluralistic ignorance,” in which citizens are unsure what other citizens believe.59

Citizens may take the fact of rebuttal itself as supplying information about the beliefs of

other citizens, and may even use this information in forming their own beliefs. The

government’s rebuttal may be a signal that other citizens believe in the conspiracy theory

– and may therefore make the theory more plausible. If the number who follow this

cognitive strategy and thus adopt a belief in the theory exceeds the number who are

persuaded by the rebuttal, the perverse result of the rebuttal may then be to increase the

number of believers.

How should government cope with this dilemma? In a typical pattern,

government plays a wait-and-see strategy: ignore the conspiracy theory until it reaches

some ill-defined threshold level of widespread popularity, and then rebut. There is a

straightforward logic to this strategy. First, when the government ignores the theory,

either the relevant audiences will draw an inference that the theory is silly, or else will

60 See Avinash K. Dixit & Robert S. Pindyck, INVESTMENT UNDER UNCERTAINTY (1994).

infer that the government cannot effectively deny it. If the conspiracy theory does not

spread despite government’s silence, the former inference is probably dominant, and

response is unnecessary. Second, there is an option value60 to the strategy of ignoring the

theory: a public rebuttal now is costly or impossible to undo, but maintaining silence now

leaves government with the option to rebut later, if it chooses to do so. On this approach,

when faced with a spreading conspiracy theory, government should wait until the

marginal expected benefits of further delay just equal the marginal expected costs of

leaving the theory unrebutted. Finally and most generally, it seems silly and infeasible to

chase after and rebut every conspiracy theory that comes to government’s attention.

However, this logic overlooks an important synergistic gain: rebutting many

conspiracy theories can reduce the legitimating effect of rebutting any one of them.

When government rebuts a particular theory while ignoring most others, the legitimating

effect arises at least in part because of a contrast between the foreground and the

background: the inference is that government has picked the theory it is rebutting out of

the larger set because this theory, unlike the others, is inherently plausible or is gaining

traction among some sectors of the mass audience. Rebutting a larger fraction of the total

background set reduces the strength of this inference as to each theory chosen for

rebuttal. The more theories government rebuts, the weaker is the implicit legitimating

signal sent by the very fact of rebuttal.

It is impossible to say, in the abstract, how great this synergistic gain may be. It

remains true that not every conspiracy theory proposed by someone somewhere (that

comes to the attention of relevant government officials) warrants a response. However,

the implication is that government should rebut more conspiracy theories than it would

otherwise choose, if assessing the expected costs and benefits of rebuttal on a theory-bytheory

basis. Because of synergy effects, government action considered over an array or

range of cases may have different total costs and benefits than when those cases are

considered one by one. Practically speaking, government might do well to maintain a

more vigorous countermisinformation establishment than it would otherwise do, one that

identifies and rebuts many more conspiracy theories would otherwise be rebutted. There

will still have to be some minimum threshold for governmental response, but the

threshold will be lower than it would be if this synergistic gain of rebutting many theories

did not exist.

2. Which audience?

Another dilemma is whether to target the supply side of the conspiracy theory or

the demand side. Should governmental responses be addressed to the suppliers, with a

view to persuading or silencing them, or rather be addressed to the mass audience, with a

view to inoculating them from pernicious theories? Of course these two strategies are not

mutually exclusive as a logical matter; perhaps the best approach is to straddle the two

audiences with a single response or simply to provide multiple responses. However, if

there are resource constraints, government may face a choice about where to place its

emphases. The question will be what mix of second-party responses (pitched to the

suppliers) and third-party responses (pitched to the mass audience) is best. Moreover,

apart from resource constraints, there are intrinsic tradeoffs across these strategies. The



Dunbar & Brad Reagan eds., 2006).

63 See, e.g., Jim Hoffman, Video of the Pentagon Attack: What Is the Government Hiding,

http://911research.com/essays/pentagon/video.html (last visited Nov. 14, 2006).

very arguments that are most convincing to the mass audience may be least convincing to

the conspiracists, and vice-versa.

We will begin with some remarks about responses addressed to the supply side.

The basic problem with pitching governmental responses to the suppliers of conspiracy

theories is that those theories, by their nature, have a self-sealing quality. They are (1)

resistant and in extreme cases invulnerable to contrary evidence,61 and (2) especially

resistant to contrary evidence offered by the government, because the government

rebuttal is folded into the conspiracy theory itself. If conspiracy theorists are responding

to the informational signals given by those whom they trust, then the government’s effort

at rebuttal seems unlikely to be effective, and might serve to fortify rather than to

undermine the original belief. (A possible solution is for government to enlist private

rebuttals; we return to this point shortly.) The most direct response to a dangerous

conspiracy theories is censorship. That response is unavailable in an open society,

because it is inconsistent with principles of freedom of expression. We could imagine

circumstances in which a conspiracy theory became so pervasive, and so dangerous, that

censorship would be thinkable. But in an open society, the need for censorship would be

correspondingly reduced. In any case censorship may well turn out to be self-defeating.

The effort to censor the theory might well be taken as evidence that the theory is true, and

censorship of speech is notoriously difficult.

After 9/11, one complex of conspiracy theories involved American Airlines Flight

77, which hijackers crashed into the Pentagon. Some theorists claimed that no plane had

hit the Pentagon; even after the Department of Defense released video frames showing

Flight 77 approaching the building and a later explosion cloud, theorists pointed out that

the actual moment of impact was absent from the video, in order to keep alive their claim

that the plane had never hit the building. (In reality the moment of impact was not

captured because the video had a low number of frames per second.62) Moreover, even

those conspiracists who were persuaded that the Flight 77 conspiracy theories were

wrong folded that view into a larger conspiracy theory. The problem with the theory that

no plane hit the Pentagon, they said, is that the theory was too transparently false,

disproved by multiple witnesses and much physical evidence. Thus the theory must have

been a straw man initially planted by the government, in order to discredit other

conspiracy theories and theorists by association.63

Government can partially circumvent these problems if it enlists nongovernmental

officials in the effort to rebut the theories. It might ensure that credible independent

experts offer the rebuttal, rather than government officials themselves. There is a

tradeoff between credibility and control, however. The price of credibility is that

government cannot be seen to control the independent experts. Although government can

supply these independent experts with information and perhaps prod them into action

from behind the scenes, too close a connection will prove self-defeating if it is exposed –

as witness the humiliating disclosures showing that apparently independent opinions on

64 See Ian Sample, Scientists Offered Cash To Dispute Climate Study, GUARDIAN, Feb. 2, 2007, at 1 (noting

that a “thinktank with close links to the Bush administration” had paid scientists to challenge a report on

global warming).

65 In fact the two may be distant relatives, but had never met. Will Sullivan, Viewing 9/11 From a Grassy

Knoll, U.S. NEWS & WORLD REP., Sept. 11, 2006.

66 Carol Morello, One Man’s Unorthodox Ideas About the 9/11 Attack on the Pentagon Go Global in a

Flash. Welcome to the Internet, Where Conspiracy Theories Flourish., WASH. POST, Oct. 7, 2004, at B01.

67 Jim Dwyer, U.S. Counters 9/11 Theories of Conspiracy, N.Y. TIMES, Sept. 2, 2006, at B1.

scientific and regulatory questions were in fact paid for by think-tanks with ties to the

Bush administration.64 Even apart from this tradeoff, conspiracy theorists may still fold

independent third-party rebuttals into their theory by making conspiratorial claims of

connection between the third party and the government. When Popular Mechanics

offered its rebuttal of 9/11 conspiracy theories, conspiracists claimed that one of the

magazine’s reporters, Ben Chertoff, was the cousin of Homeland Security Secretary

Michael Chertoff and was spreading disinformation at the latter’s behest.65

Because of these difficulties, many officials dismiss direct responses to the

suppliers of conspiracy theorists as an exercise in futility. Rather, they implicitly frame

their responses to the third-party mass audience, hoping to stem the spread of conspiracy

theories by dampening the demand rather than by reducing the supply. Philip Zelikow,

the executive director of the 9/11 commission, says that “[t]he hardcore conspiracy

theorists are totally committed. They’d have to repudiate much of their life identity in

order not to accept some of that stuff. That’s not our worry. Our worry is when things

become infectious . . . . [t]hen this stuff can be deeply corrosive to public understanding.

You can get where the bacteria can sicken the larger body.”66 Likewise, when the

National Institute of Standards and Technology issued a fact sheet to disprove the theory

that the World Trade Center was brought down by a controlled demolition, the

spokesman stated that “[w]e realize this fact sheet won’t convince those who hold to the

alternative theories that our findings are sound. In fact, the fact sheet was never intended

for them. It is for the masses who have seen or heard the alternative theory claims and

want balance.”67

The problem with this line of argument, however, is that it takes the existence of a

hard core as a given. This is premature; we will suggest below that if the hard core arises

for certain identifiable reasons, it can be broken up or at least muted by government

action. Furthermore, there are intrinsic costs to the strategy of giving up on the hard core

and directing government efforts solely towards inoculating the mass audience. For one

thing, the hard core may itself provide the most serious threat. For another, a response

geared to a mass audience (whether or not nominally pitched as a response to the

conspiracy theorists) will lead some to embrace rather than reject the conspiracy theory

the government is trying to rebut. This is the legitimation dilemma again: to begin a

program of inoculation is to signal that the disease is already widespread and threatening.

Under pluralistic ignorance, the perverse result may actually be to spread the conspiracy

theory further.

3. Cognitive infiltration

Rather than taking the continued existence of the hard core as a constraint, and

addressing itself solely to the third-party mass audience, government might undertake

68 Neil MacFarquhar, At State Dept., Blog Team Joins Muslim Debate, N.Y. TIMES, Sept. 22, 2007, at A1.

(legal) tactics for breaking up the tight cognitive clusters of extremist theories, arguments

and rhetoric that are produced by the hard core and reinforce it in turn. One promising

tactic is cognitive infiltration of extremist groups. By this we do not mean 1960s-style

infiltration with a view to surveillance and collecting information, possibly for use in

future prosecutions. Rather, we mean that government efforts might succeed in

weakening or even breaking up the ideological and epistemological complexes that

constitute these networks and groups.

How might this tactic work? Recall that extremist networks and groups,

including the groups that purvey conspiracy theories, typically suffer from a kind of

crippled epistemology. Hearing only conspiratorial accounts of government behavior,

their members become ever more prone to believe and generate such accounts.

Informational and reputational cascades, group polarization, and selection effects suggest

that the generation of ever-more-extreme views within these groups can be dampened or

reversed by the introduction of cognitive diversity. We suggest a role for government

efforts, and agents, in introducing such diversity. Government agents (and their allies)

might enter chat rooms, online social networks, or even real-space groups and attempt to

undermine percolating conspiracy theories by raising doubts about their factual premises,

causal logic or implications for political action.

In one variant, government agents would openly proclaim, or at least make no

effort to conceal, their institutional affiliations. A recent newspaper story recounts that

Arabic-speaking Muslim officials from the State Department have participated in

dialogues at radical Islamist chat rooms and websites in order to ventilate arguments not

usually heard among the groups that cluster around those sites, with some success.68 In

another variant, government officials would participate anonymously or even with false

identities. Each approach has distinct costs and benefits; the second is riskier but

potentially brings higher returns. In the former case, where government officials

participate openly as such, hard-core members of the relevant networks, communities and

conspiracy-minded organizations may entirely discount what the officials say, right from

the beginning. The risk with tactics of anonymous participation, conversely, is that if the

tactic becomes known, any true member of the relevant groups who raises doubts may be

suspected of government connections. Despite these difficulties, the two forms of

cognitive infiltration offer different risk-reward mixes and are both potentially useful


There is a similar tradeoff along another dimension: whether the infiltration

should occur in the real world, through physical penetration of conspiracist groups by

undercover agents, or instead should occur strictly in cyberspace. The latter is safer, but

potentially less productive. The former will sometimes be indispensable, where the

groups that purvey conspiracy theories (and perhaps themselves formulate conspiracies)

formulate their views through real-space informational networks rather than virtual

networks. Infiltration of any kind poses well-known risks: perhaps agents will be asked

to perform criminal acts to prove their bona fides, or (less plausibly) will themselves

become persuaded by the conspiratorial views they are supposed to be undermining;

perhaps agents will be unmasked and harmed by the infiltrated group. But the risks are

69 See SUNSTEIN, supra note 43.

70 See Federal Election Comm’n v. Akins, 524 U.S. 11 (1998).

71 See Jerry Markon, Pentagon Releases Videos of 9/11 Plane Crash; Group Wanted to Counter 9/11

Conspiracy Theories, WASH. POST, May 17, 2006, at B01.

generally greater for real-world infiltration, where the agent is exposed to more serious


All these risk-reward tradeoffs deserve careful consideration. Particular tactics

may or may not be cost-justified under particular circumstances. Our main suggestion is

just that, whatever the tactical details, there would seem to be ample reason for

government efforts to introduce some cognitive diversity into the groups that generate

conspiracy theories. Social cascades are sometimes quite fragile, precisely because they

are based on small slivers of information. Once corrective information is introduced,

large numbers of people can be shifted to different views. If government is able to have

credibility, or to act through credible agents, it might well be successful in dislodging

beliefs that are held only because no one contradicts them. Likewise, polarization tends

to decrease when divergent views are voiced within the group.69 Introducing a measure

of cognitive diversity can break up the epistemological networks and clusters that supply

conspiracy theories.

C. A Role for Law, and Courts?

So far we have detailed some dilemmas facing government officials and have

suggested some policy responses. What if anything is the role of law, and courts, in these

matters? The principal point of contact between the legal system and the issues discussed

here is the Freedom of Information Act (FOIA), which creates a presumption of

transparency for documents held by administrative agencies and executive institutions.

Unless the government can show that the requested information falls within one of a

designated list of exceptions, there is a legal right to disclosure, and the Supreme Court

has created a broad concept of “informational standing”70 to permit interested groups and

citizens to enforce that right.

FOIA becomes relevant when the government holds, and declines to disclose,

information that might rebut a circulating conspiracy theory. An example involves the

disclosure of the Department of Defense video involving Flight 77’s crash into the

Pentagon on 9/11. A pro-transparency group, Judicial Watch, filed a FOIA request to

obtain the video, but the Defense Department declined, saying that the video was to be

used in the trial of Zacharias Moussaoui. Judicial Watch filed suit to force disclosure,

with the avowed objective of using the video to rebut the conspiracy theories surrounding

Flight 77. However, when the Moussaoui trial ended the government released the video

before the lawsuit could be decided.71

The details of the case only suggest the larger question that it poses: should

courts, and law, force the executive to disclose information that a litigant claims would

help to rebut conspiracy theories? If the answer is yes, then control over the timing and

nature of the executive’s responsive strategy will be partially transferred to litigating

groups and judges. If the answer is no, the executive will retain full control.

We suggest that the critical question is a comparative institutional one. Will

adding judicial involvement, itself partially determined by the decisions of litigating

72 In theory courts might do so by reducing the variance associated with these decisions – fewer big

mistakes in either direction – but we will ignore this possibility, which is never adduced to support judicial

intervention. Rather, the standard claim is that government errs systematically, in a particular direction –

insufficient disclosure.

73 Cf. Kenneth A. Shepsle, Congress is a “They,” Not an “It”: Legislative Intent as Oxymoron, 12 INT’L

REV. L. & ECON. 239 (1992).

groups, create a net improvement in the government’s overall response strategy? In

general, two conditions must hold for this to be so. First, there must be some mechanism

that causes the executive systematically to make suboptimal decisions about whether,

when, and how to release information that might rebut conspiracy theories. If executive

branch decisions are unbiased, in the sense that they are accurate on average (even if

randomly mistaken in particular cases), then courts will be hard pressed to improve upon

them.72 Second, even if the executive branch does make predictable errors, the litigation

process must have some relative institutional advantage in this regard; it must be able to

improve upon the executive’s choices. The benchmark is not optimal disclosure, but the

disclosure that actually results from adding litigation-based oversight to executive branch


There is little reason to think, in general, that both of these conditions will usually

be met. In the Flight 77 case, Judicial Watch offered no concrete reason why the

executive would erroneously balance the relative benefits and costs of disclosing the

information immediately, including (1) the expected gain to the government’s efforts to

rebut the Flight 77 conspiracy theories; (2) the expected costs to national security of

disclosing details about the Department of Defense’s surveillance activities and methods;

and (3) the lost option value of disclosing later, rather than now. Judicial Watch noted

that (2) was low, because most of the information was already public in one way or

another, and this seems plausible. However, (1) was also low. As we have detailed

above, the video’s release did little to squelch the Flight 77 conspiracy theorists, who

promptly folded the video into their theories. Factor (3) is hard to estimate; but it is clear

that when courts require disclosure in such situations, the value of the option to make a

later disclosure is systematically destroyed. Even if the executive would make mistakes

about these factors, viewed in the light of hindsight, it is plausible to think that those

mistakes will tend to be randomly distributed, in part because governmental interests are

on both sides of the balance. In any event, Judicial Watch offered no reason to think that

the litigation process would systematically do better. In general, the argument for

compelled disclosure is strongest when the executive branch is likely to be systematically

biased against disclosure, for self-serving reasons; this is the argument that most

plausibly justifies FOIA itself. When a conspiracy theory is at work, there is unlikely to

be any systematic bias against disclosure, because the executive has a strong incentive to

correct the theory.

To be sure, the first of the two conditions we have mentioned – that executive

branch disclosures are not optimally geared to suppressing conspiracy theories – does

seem plausible under certain conditions. Because the executive is partially a they, not an

it,73 its (their) efforts to respond to conspiracy theories may be hampered by poor

coordination across agencies or executive departments. Perhaps, for example, one

agency holds information that it refuses to disclose or even transmit within the executive

branch, although another agency or another branch of government needs it to combat a


75 DONALD L. HOROWITZ, THE COURTS AND SOCIAL POLICY (1977); Cf. Frank I. Michelman, Politics and

Values or What’s Really Wrong With Rationality Review, 13 Creighton L. Rev. 487 (1979).

76 See, e.g., U.S. Dep’t of Justice v. Reporters Comm. for Freedom of the Press, 489 U.S. 749, 771-73


conspiracy theory. Here there is a kind of intra-executive externality, with one agency

failing to take into account the full costs of its actions to other institutions. Moreover, if

there are systematic incentives for overclassification and excessive government secrecy –

a claim that is often heard but rarely fleshed out with concrete mechanisms – then there

will be systematic error in government responses, with too little disclosure or disclosure

coming too late.

However, these possibilities are balanced by equally speculative possibilities

cutting in other directions. If the executive is a they, not an it, it may also be the case that

a given agency does not fully take into account the harms of disclosure to the mission of

other agencies, and the problem will be too much disclosure or premature disclosure

(from the standpoint of the latter agencies). Intra-executive externalities and agency

incentives may cut in either direction; their net effect is hard to assess in the abstract, and

there is little reason to think they necessarily create a systematic skew in one direction or

another. Furthermore, addressing conspiracy theories is not the only thing the executive

does. Even if an agency is not acting optimally with respect to that goal, it may be acting

in a way that promotes good policy (somehow defined) overall.

Most importantly, there is little general reason to think that the second condition –

that litigating groups and judges can improve upon the executive’s choices – will often be

met. First, if agencies may hold motivations or face incentives that distort the optimal

approach to information disclosure, courts suffer from deficits of expertise and

policymaking ability that hamper their efforts to make things better. Here a serious

problem is that courts decide one case at a time. While this practice has many benefits,74

it makes it difficult for courts to gain a systemic view75 across an array of cases in order

to decide whether an agencies’ decisions are systematically distorted, or to evaluate

whether inter-executive externalities are occurring.

Second, suppose that the court does know (better than the executive) how and

when to disclose information in order to rebut a conspiracy theory. The problem is that

the court may be legally constrained not to act optimally in any event. There is no

necessary connection between the timing of the lawsuit and the optimal timing of

disclosure for addressing the relevant conspiracy theory. In the Judicial Watch case, the

optimal time of disclosure may have been never, given the low benefits; it may also have

been at some time in the future. The court, however, is legally constrained from acting

on its open-ended assessment. It may decide that the plaintiff prevails and disclosure

occurs, or not, but in general it may not fine-tune the timing of disclosure at will.

In all of these remarks, we have made two assumptions that cabin the analysis; we

are not offering a general account of FOIA litigation. We have assumed first of all that –

as in the Judicial Watch litigation – the plaintiff’s avowed purpose is to force a disclosure

that in the plaintiff’s judgment will rebut a spreading conspiracy theory. In internal legal

terms, this is irrelevant; the Supreme Court has repeatedly stated that reviewing courts

should not consider the specific interests of the requester in obtaining FOIA disclosure.76

77 See, e.g., Ctr. for Nat’l Sec. Studies v. U.S. Dep’t of Justice, 331 F.3d 918, 928-29 (D.C. Cir. 2003).


79 Marvin Zonis & Craig M. Joseph, Conspiracy Thinking in the Middle East, 15 POL. PSYCHOL. 443, 445


80 Cf. Krueger, supra note 10.

However, it is certainly relevant from an external standpoint, where the question is how

to assess the institutional capacities of relevant actors. Where the aim of all concerned

actors, including the plaintiffs, is to supply an optimal response to conspiracy theories

rather than to assert other interests, there are special grounds for doubting that the

litigation process can improve upon executive branch choices.

We have also assumed that the relevant statutes are sufficiently ambiguous or

vague that both agencies and courts are at least in part making policy choices, rather than

enforcing the law in any simple sense. Where this is not so, and the commands of FOIA

are clear, courts should enforce them. If the resulting disclosure is not optimally timed,

the problem lies with the statute (as applied). In general, however, this is not the

situation such cases will pose. Rather the agency resists disclosure under a vague or

broadly worded FOIA exemption, and perhaps also by invoking principles such as the

“mosaic theory,”77 according to which government may resist disclosures that are

innocuous in themselves but that can be assembled into a larger picture damaging to

national security. If the reviewing court does not face a clear legal command, and if the

court lacks confidence (as we do) that the litigation process will on average produce

better responses to conspiracy theorizing, then the court should stay its hand.

D. A Note on Conspiracy Theories Abroad

Our focus has been on domestic conspiracy theories, although some of the

relevant considerations are constant across both domestic and foreign audiences.

Conspiracy theories flourish in many Middle Eastern and predominantly Muslim

countries, so much so that there is a small literature asking why Muslims are so prone to

conspiracy theorizing.78 (One paper by Freudian psychologists even ascribes this “fact”

to Muslim child-rearing practices79; we are skeptical.) If many Muslims abroad are

prone to conspiracy theorizing, so too are many non-Muslims in the United States, as the

evidence given above demonstrates. On the other hand, we have conjectured that there is

a causal link between the prevalence of conspiracy theories and the relative absence of

civil liberties and a well-functioning marketplace of ideas,80 so it is unsurprising that

such theories are even more widespread in the Muslim world than in the United States.

Overall, conspiracy theorizing is undoubtedly virulent in the Muslim world, has a sharply

anti-American inflection, and poses problems that are somewhat distinctive, so a brief

discussion is warranted.

On the diagnostic side, it is highly likely that the virulence of conspiracy

theorizing in Muslim nations has a great deal to do with social cascades and group

polarization, and with weak civil liberties and the lack of a robust market for ideas in

many of those nations. In terms of our suggested policy responses, the foreign setting is

both a worse and a better environment for the U.S. government. It is worse in that the

nature of the relevant institutions and audiences in the Muslim world sharpens many of

the dilemmas and tradeoffs we have described. Typically, the audience is antecedently

skeptical, in the extreme, of anything said by United States officials; shortly we will see

81 Justin Rood, U.S. Government Gave Airtime to Terrorists, Official Admits, ABC NEWS, May 22, 2007,


82 Lynne Duke, The Word at War; Propaganda? Nah, Here’s the Scoop, Say the Guys Who Planted Stories

in Iraqi Papers, WASH. POST, Mar. 26, 2006, at D01.

that this creates enormous pressure for the U.S. to engage in various forms of covert or

anonymous speech. The marketplace of ideas, in many Muslim nations, is institutionally

fragile or dominated by powerful governments. Civil liberties, including free speech, are

often shaky. The upside to the foreign setting, however, is that on some dimensions the

U.S. enjoys greater freedom of action, in part because domestic U.S. politics will tolerate

some actions abroad that it would not tolerate if taken at home.

We begin with the difficulties. The foreign setting sharpens one of the central

tradeoffs we have identified: to enhance the credibility of speech that debunks conspiracy

theories, the government must surrender some degree of control over the institutions of

speech. In 2004, the U.S. government set up a broadcast network for the Middle East –

Al-Hurrah, “the Free One” – that puts out news and third-party opinion. In May 2007, a

House subcommittee called a hearing to investigate reports that Al-Hurrah had broadcast

“terrorist” content, including “a 68-minute call to arms against Israelis by a senior figure

of the terrorist group Hezbollah; [and] deferential coverage of Iranian President

Mahmoud Ahmadinejad’s Holocaust denial conference . . . ”.81 Legislators sharply

questioned officials of the Broadcasting Board of Governors, the government corporation

that ultimately funds Al-Hurrah, and those officials had to promise to address the

legislators’ concerns. Those problems, however, were part and parcel of a broader

strategy for enhancing credibility by permitting other viewpoints and voices on the air.

In general, in order to enhance its credibility with antecedently skeptical Muslim

audiences, the U.S. government must go a long way towards surrendering control over

the content of its speech (or must speak anonymously, a strategy that carries its own

risks, as we mention next). However, as this episode reveals, domestic political

constraints may preclude whatever mix of credibility and control is optimal from the

standpoint of dampening conspiracy theories or promoting U.S. public relations goals

more generally.

The alternative to surrendering control over the content of the government’s

responses, in order to enhance credibility, is for government officials or agents to speak

anonymously. A mini-scandal erupted in 2006 when U.S. newspapers revealed that the

Lincoln Group, an independent contractor of “influence services,” had paid Iraqi

newspapers to publish hundreds of “news stories” written by U.S. military personnel but

not identified as such, most of which portrayed events in Iraq in cheery terms or rebutted

circulating conspiracy theories.82 The stories were factually true, but selective. As

against the obvious moral objections to this practice, the Lincoln Group argued that

speech identified as stemming from U.S. sources would, even if true, credible and

important, be utterly discounted by the Iraqi audience, leaving the field entirely to

conspiratorial and hostile rumors. On this view the implicit lie of planting “news” stories

not identified to their true sources is necessary, in a deliberative environment that is

already warped, to the goal of putting all relevant information before a quasi-rational

audience. Where the marketplace of ideas is already malfunctioning, in the sense that

relevant audiences discount to zero statements that should carry positive weight, practices

83 Id.

84 Editorial, Hearts, Minds and Padlocks, N.Y. TIMES, Mar. 30, 2004, at A20.

85 Id.

86 Roula Khalaf, US Takes An Optimistic View in Battle for Hearts and Minds in the Arab World: The New

American-sponsored al-Hurra Channel Aims to Reach Young People With Help From Some Good-News

Stories, FIN. TIMES, Jan. 15, 2004, at 11.

that would not be permissible in a well-developed liberal state might be permissible on

second-best grounds.

A better objection to this practice may instead be tactical. By outsourcing this

form of quasi-propaganda to an independent contractor whose participation would sooner

or later be brought to light, the U.S. government fell between two stools, obtaining

neither the credibility benefits of full transparency nor the credibility benefits of totally

anonymous speech. Reuel Marc Gerecht, a former CIA case officer, commented that

“[t]he historical parallel would be the [CIA’s] efforts during the Cold War to fund

magazines, newspapers and journalists who believed that the West should triumph over

communism. Much of what you do ought to be covert, and, certainly, if you contract it

out, it isn’t.”83

So far we have discussed the distinctive difficulties of the foreign setting. On

other dimensions, however, the foreign setting loosens various legal and political

constraints, allowing the U.S. government greater freedom in responding to conspiracy

theories. In 2004, the U.S. administrator for Iraq, L. Paul Bremer, ordered troops to shut

down a weekly newspaper in Baghdad that had propounded false conspiracy theories

damaging to the U.S., such as a story that “an American missile, not a terrorist car bomb,

had caused an explosion that killed more than 50 Iraqi police recruits.”84 Whether this

sort of action does more harm than good, in similar environments, is a complicated

question, depending on difficult judgments about the etiology of conspiracy theories, the

consequences of censorship, and the efficacy of U.S. counterspeech. On the one hand,

there are the familiar arguments that censorship attracts attention to the censored speech

or publication and fuels further conspiracy theorizing; perhaps, the inference might run,

the U.S. is moving against a particular rumor because it is true, or is moving against a

particular paper because it is exposing actual U.S. conspiracies. Furthermore, censorship

might just drive the conspiracy theories underground, to be spread and mutated by

personal rumor-mongering that is less susceptible to focused rebuttal.

On the other hand, the peculiar environment in which Bremer acted may weigh in

favor of a policy of censoring publication of conspiracy theories. One editorial argued

that “[t]he occupation authorities have plenty of means, including their own television

station, to get out a more favorable message.”85 However, this ignores the effect

discussed above, that the antecedent skepticism of the Iraqi audience is so strong that any

U.S. statements, even if true, credible and important, will be ignored altogether. With an

audience already thoroughly in the grip of conspiracy theories, open counterspeech may

simply be more grist for the conspiratorial mill. Consider that when Al-Hurra began its

operations, a conspiracy theory quickly circulated, claiming that the short-term contracts

given to Al-Hurra personnel showed that the station was set up only to bolster George W.

Bush’s reelection campaign, and would presumably be shut down after the election.86

Given the extremely low efficacy of U.S. counterspeech in this sort of environment, the

realistic options may be limited to censorship and anonymous or quasi-anonymous

counterspeech in the style of the Lincoln Group. Whatever the merits of these pragmatic

and tactical questions, the availability of censorship gives U.S. officials operating in

foreign countries an extra instrument for coping with conspiracy theories, one that is not

available in the domestic arena due to both legal and political constraints.


Our goal here has been to understand the sources of conspiracy theories and to

examine potential government responses. Most people lack direct or personal information

about the explanations for terrible events, and they are often tempted to attribute such

events to some nefarious actor. The temptation is least likely to be resisted if others are

making the same attributions. Conspiracy cascades arise through the same processes that

fuel many kinds of social errors. What makes such cascades most distinctive, and

relevantly different from other cascades involving beliefs that are both false and harmful,

is their self-insulating quality. The very statements and facts that might dissolve

conspiracy cascades can be taken as further evidence on their behalf. These points make

it especially difficult for outsiders, including governments, to debunk them.

Some conspiracy theories create serious risks. They do not merely undermine

democratic debate; in extreme cases, they create or fuel violence. If government can

dispel such theories, it should do so. One problem is that its efforts might be

counterproductive, because efforts to rebut conspiracy theories also legitimate them. We

have suggested, however, that government can minimize this effect by rebutting more

rather than fewer theories, by enlisting independent groups to supply rebuttals, and by

cognitive infiltration designed to break up the crippled epistemology of conspiracyminded

groups and informationally isolated social networks.

This paper can be downloaded free of charge from the Social Science Research Network at:


Harvard University Law School

Public Law & Legal Theory Research Paper Series

University of Chicago Law School

Public Law & Legal Theory Research Paper Series

Paper No. 199


University of Chicago Law School

Law & Economics Research Paper Series

Paper No. 387

Conspiracy Theories


University of Chicago – Law School


Harvard University – Harvard Law School

This paper can be downloaded free of charge from the

Social Science Research Network at:


Electronic copy available at: http://ssrn.com/abstract=1084585

Preliminary draft 1/15/08

All rights reserved

Conspiracy Theories

Cass R. Sunstein*

Adrian Vermeule**

AbstractPreliminary draft 1/15/08

All rights reserved

Conspiracy Theories

Cass R. Sunstein*

Adrian Vermeule**


Many millions of people hold conspiracy theories; they believe that powerful

people have worked together in order to withhold the truth about some important

practice or some terrible event. A recent example is the belief, widespread in some parts

of the world, that the attacks of 9/11 were carried out not by Al Qaeda, but by Israel or

the United States. Those who subscribe to conspiracy theories may create serious risks,

including risks of violence, and the existence of such theories raises significant

challenges for policy and law. The first challenge is to understand the mechanisms by

which conspiracy theories prosper; the second challenge is to understand how such

theories might be undermined. Such theories typically spread as a result of identifiable cognitive blunders, operating in conjunction with informational and reputational influences. A distinctive feature of conspiracy theories is their self-sealing quality.

Conspiracy theorists are not likely to be persuaded by an attempt to dispel their theories;

they may even characterize that very attempt as further proof of the conspiracy. Because

those who hold conspiracy theories typically suffer from a “crippled epistemology,” in

accordance with which it is rational to hold such theories, the best response consists in

cognitive infiltration of extremist groups. Various policy dilemmas, such as the question

whether it is better for government to rebut conspiracy theories or to ignore them, are

explored in this light.

“The truth is out there”:1 conspiracy theories are all around us. In August 2004, a

poll by Zogby International showed that 49 percent of New York City residents, with a

* Karl N. Llewellyn Distinguished Service Professor of Jurisprudence, University of Chicago.

** Professor of Law, Harvard Law School. Thanks to Mark Tushnet for helpful conversations, to Eric

Posner and Andrei Shleifer for valuable comments, and to Elisabeth Theodore for excellent research assistance.

1 This slogan was popularized by the television show The X-Files, see http://en.wikipedia.org/wiki/The_XFiles.

9/11 conspiracy theorists often call themselves the 9/11 Truth Movement. See The 9/11 Truth

Movement, http://www.911truth.org (last visited Nov. 14, 2007).

10 See Alan Krueger, WHAT MAKES A TERRORIST? 75-82 (2007). Krueger believes that low civil liberties cause terrorism, but acknowledges that his data are also consistent with the hypothesis that terrorism causes governments to reduce civil liberties. See id. at 148. Of course, the two effects may both occur, in a mutually reinforcing pattern. Following Krueger, we assume that low civil liberties tend to produce terrorism, a hypothesis that is supported by the mechanisms we adduce.

margin of error of 3.5 percent, believed that officials of the U.S. government “knew in

advance that attacks were planned on or around September 11, 2001, and that they

consciously failed to act.”2 In a Scripps-Howard Poll in 2006, with an error margin of 4

percent, some 36 percent of respondents assented to the claim that “federal officials either

participated in the attacks on the World Trade Center or took no action to stop them.”3

Sixteen percent said that it was either very likely or somewhat likely that “the collapse of

the twin towers in New York was aided by explosives secretly planted in the two


2 Zogby International, Half of New Yorkers Believe US Leaders Had Foreknowledge of Impending 9-11

Attacks and “Consciously Failed” To Act, Aug. 30, 2004, http://zogby.com/news/ReadNews.dbm?ID=855.

3 Thomas Hargrove & Guido H. Stempel III, A Third of U.S. Public Believes 9/11 Conspiracy Theory,



4 Id.

5 One in 5 Canadians Sees 9/11 as U.S. Plot – Poll, REUTERS, Sept. 11, 2006.

6 Matthew A. Gentzkow & Jesse M. Shapiro, Media, Education and Anti-Americanism in the Muslim

World, 18 J. ECON. PERSPECTIVES 117, 117 (2004)

7 Id. at 120.


CONCEPTIONS OF CONSPIRACY (Carl F. Graumann & Serge Moscovici eds., 1988).

9 There is also a body of work that collects many interesting examples of conspiracy theories, but without

any sustained analytic approach. See, e.g., Michael Barkun, A CULTURE OF CONSPIRACY (2003); Daniel

Pipes, CONSPIRACY (1997). For a treatment of conspiracy theories from the standpoint of cultural studies,

see Mark Fenster, CONSPIRACY THEORIES (1999).

I. Definitions and Mechanisms

11 See note 8 supra.



OF THE AIDS EPIDEMIC (1988) (suggesting AIDS was the product of a biowarfare program targeting gay people); Don Phillips, Missile Theory Haunts TWA Investigation; Despite Lack of Evidence and Officials’

Denials, Some Insist Friendly Fire Caused Crash, WASH. POST, Mar. 14, 1997, at A03; 149 CONG. REC. S10022 (daily ed. July 28, 2003) (statement of Sen. Inhofe) (“With all the hysteria, all the fear, all the

phony science, could it be that manmade global warming is the greatest hoax ever perpetrated on the

American people? I believe it is.”); David Mills, Beware the Trilateral Commission!; The Influential World

Panel Conspiracy Theorists Love to Hate, WASH. POST, Apr. 25, 1992, at H1 (describing various

conspiracy theories about the Commission); William F. Pepper, AN ACT OF STATE: THE EXECUTION OF

MARTIN LUTHER KING (2003) (arguing that the military, the CIA, and others within the government

conspired to kill King); Kevin Diaz, Findings Don’t Slow Conspiracy Theories on Wellstone Crash; An

Official Investigation Has Focused on Pilot Error and Weather. Some Observers Still Have Suggested a

Political Plot., STAR TRIBUNE (Minn.), June 3, 2003, at A1; Patty Reinert, Apollo Shrugged: Hoax Theories

About Moon Landings Persist, HOUSTON CHRON., Nov. 17, 2002, at A1.

13 See Bob Woodward & Carl Bernstein, ALL THE PRESIDENT’S MEN (1974); George Lardner Jr. & John

Jacobs, Lengthy Mind-Control Research by CIA Is Detailed, WASH. POST, Aug. 3, 1977, at A1;

Memorandum from L. L. Lemnitzer, Chairman, Joint Chiefs of Staff, to the Secretary of Defense,

Justification for U.S. Military Intervention in Cuba (Mar. 13, 1962), available at


15 See Karl R. Popper, The Conspiracy Theory of Society, in CONSPIRACY THEORIES, supra note 8; see also


16 Id.


18 An illuminating discussion is Edna Ullmann-Margalit, The Invisible Hand and the Cunning of Reason, 64 SOC.

RES. 181 (1997).

19 See Taleb, supra note.

20 See, e.g., James Risen & Eric Lichtblau, Bush Lets U.S. Spy on Callers Without Courts, N.Y. TIMES, Dec.

16, 2005, at A1; Jane Mayer, The Black Sites: A Rare Look Inside the C.I.A.’s Secret Interrogation

Program, THE NEW YORKER, Aug. 13, 2007, at 46.

21 Consider here Amartya Sen’s finding that in the history of the world, no famine has occurred in a nation with a free press and democratic elections. See Amartya Sen, Poverty and Famines (1983). Of course it would be excessive to infer that in authoritarian nations, famines are a “conspiracy” of the authoritarians.

22 Brian L. Keeley, Of Conspiracy Theories, in CONSPIRACY THEORIES, supra note 8, at 46, 56-57.

23 Quoted in id. at 57.

24 Imre Lakatos, Falsification and Methodology of Scientific Research Programmes, in CRITICISM AND THE

GROWTH OF KNOWLEDGE 91 (Imre Lakatos & Alan Musgrave eds., 1970); see Steve Clarke, Conspiracy

Theories and Conspiracy Theorizing, in CONSPIRACY THEORIES, supra note 8, at 78.


GROUP (2005).

26 Keeley, supra note 22, at 55-56.

27 See Richard Hofstader, The Paranoid Style in American Politics, in THE PARANOID STYLE IN AMERICAN

POLITICS AND OTHER ESSAYS (1979); Robert S. Robins & Jerrold M. Post, POLITICAL PARANOIA (1997).

See, e.g., Deiter

Groh, The Temptation of Conspiracy Theory, in CHANGING CONCEPTIONS OF CONSPIRACY, supra note 8, at

1. Our suggestion is that the lens of psychopathology is not helpful, whether it is interpreted in individual

or collective terms.

28 See Erich Wulff, Paranoic Conspiratory Delusion, in CHANGING CONCEPTIONS OF CONSPIRACY, supra

note 8, at 172.

29 There is an immense and growing literature on this question. For examples, with relevant citations, see

Glaeser, supra; Sendhil Mullainathan and Andrei Shleifer, The Market for News, 95 AM. ECON. REV. 1031

(2005); Sendhil Mullainathan and Andrei Shleifer, Media Bias (2002), available at

http://www.nber.org/papers/w9295.pdf; Edward Glaeser and Cass R. Sunstein, Extremism and Social

Learning, J. LEGAL ANALYSIS (forthcoming 2008).

30 Russell Hardin, The Crippled Epistemology of Extremism, in POLITICAL RATIONALITY AND EXTREMISM

3, 16 (Albert Breton et al. eds., 2002).

31 Id. Of course it is also true that many extremists have become extreme, or stayed extreme, after being

exposed to a great deal of information on various sides.

32 See KRUEGER, supra note 10, at 75-82.

33 See id. at 89-90.