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Conspiracy Theories and Other Dangerous Ideas

About The Book

The most controversial essays from the bestselling author once called the most dangerous man in America—collected for the first time.

The nation’s most-cited legal scholar who for decades has been at the forefront of applied behavioral economics, and the bestselling author of Nudge and Simpler, Cass Sunstein is one of the world’s most innovative thinkers in the academy and the world of practical politics. In the years leading up to his confirmation as the administrator of the White House Office of Information and Regulatory Affairs (OIRA), Sunstein published hundreds of articles on everything from same-sex marriage to cost-benefit analysis. Conspiracy Theories and Other Dangerous Ideas is a collection of his most famous, insightful, relevant, and inflammatory pieces. Within these pages you will learn:

• Why perfectly rational people sometimes believe crazy conspiracy theories
• What wealthy countries should and should not do about climate change
• Why governments should allow same-sex marriage, and what the “right to marry” is all about
• Why animals have rights (and what that means)
• Why we “misfear,” meaning get scared when we should be unconcerned and are unconcerned when we should get scared
• What kinds of losses make us miserable, and what kinds of losses are absolutely fine
• How to find the balance between religious freedom and gender equality
• And much more...

Cass Sunstein is a unique, controversial, and exciting voice in the political world. A man who cuts through the fog of left vs. right arguments and offers logical, evidence-based, and often surprising solutions to today’s most challenging questions.


Conspiracy Theories & Other Dangerous Ideas



Conspiracy theories are all around us. In August 2004, a poll by Zogby International found that 49 percent of New York City residents believed that officials of the US government “knew in advance that attacks were planned on or around September 11, 2001, and that they consciously failed to act.”1 In a Scripps-Howard poll in 2006, some 36 percent of respondents agreed that “federal officials either participated in the attacks on the World Trade Center or took no action to stop them.”2 Another 16 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 buildings.”3

Among normally sober-minded Canadians, a September 2006 poll found that 22 percent believed 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.”4 In a poll conducted in seven Muslim countries, 78 percent of the respondents did not believe that the 9/11 attacks were carried out by Arabs.5 The most popular account in these countries was that 9/11 was the work of the US or Israeli government.6

In 2013, a poll in the United States found that 37 percent of Americans believe that climate change is a hoax and that 21 percent believe that the US government is hiding evidence of the existence of aliens.7 In China, a bestseller attributed various events (the rise of Adolf Hitler, the Asian financial crisis of 1997–98, and environmental destruction in the developing world) to the Rothschild banking dynasty. The analysis was apparently read and debated at high levels of business and government.8 In the aftermath of the explosions at the Boston Marathon in 2013, it was rumored that one of the bombers was an FBI informant and that the organizers of the marathon knew about the attacks in advance. Throughout American history, race-related violence has often been spurred by false rumors, generally pointing to alleged conspiracies by one group against another.9 And with the help of the internet, conspiracy theories can be made available to the world in an instant. There is even a Conspiracy Theories & Secret Societies for Dummies.

What causes such theories to arise and spread? Are they important and even threatening, or merely trivial and even amusing? What, if anything, can and should government do about them? The principal goal of this chapter is to sketch some psychological and social mechanisms that produce, sustain, and spread conspiracy theories. An understanding of those processes helps to identify the circumstances in which such theories should be taken seriously and may warrant some kind of official response.

The main (though far from exclusive) focus involves conspiracy theories relating to (and helping to inspire) terrorism, including theories that are connected with or postdate the 9/11 attacks. These theories exist within the United States and, even more virulently, in foreign countries, especially Muslim nations. The existence of both domestic and foreign conspiracy theories is no trivial matter; they can help give rise to serious risks, including risks of violence. While terrorism-related theories are hardly the only ones of interest, they provide a crucial testing ground.

While most people do not accept false conspiracy theories, they can nonetheless hear the voice of their inner conspiracy theorist, at least on occasion. As we shall see, conspiracy theorizing is, in a sense, built into the human condition. As we shall also see, an understanding of conspiracy theories has broad implications for the spread of information and beliefs. Many erroneous judgments, including those that play an important and damaging role in the political arena, are products of the same forces that produce conspiracy theories.

If we are able to see how conspiracy theories arise, we will understand the dynamics behind the dissemination of false rumors and false beliefs of many different kinds. And if we are able to understand how to counteract such theories, we will have some clues about how to correct widespread falsehoods more generally—and about why some efforts at correction fail while others succeed.


There has been much discussion of what, exactly, counts as a conspiracy theory, and about what, if anything, is wrong with those who believe one. Let us bracket the most difficult questions here and suggest more pragmatically that a conspiracy theory can be counted as such if it is an effort to explain some event or practice by referring to the secret machinations of powerful people who have also managed to conceal their role.

Consider, for example, the following beliefs, which have found varying degrees of acceptance in different communities:

• the US Central Intelligence Agency (CIA) was responsible for the 1963 assassination of President John F. Kennedy;

• doctors deliberately manufactured the AIDS virus;

• the 1996 explosion and crash of TWA Flight 800 off the coast of Long Island was caused by a US military missile;

• the theory of climate change is a deliberate fraud;

• civil rights leader Dr. Martin Luther King Jr. was killed by federal agents in 1968;

• the 2002 plane crash that killed Paul Wellstone, the liberal Democratic senator from Minnesota, was engineered by Republican politicians;

• the Apollo 11 moon landing was staged and never actually occurred;

• the Rothschilds and other Jewish bankers have been responsible for the deaths of presidents and for economic distress in Asian nations;

• the Great Depression was a result of a plot by wealthy people to reduce workers’ wages.

Some conspiracy theories have, of course, turned out to be true. The Watergate hotel room used by the Democratic National Committee was, in fact, bugged by Republican officials in 1972, operating at the behest of the White House. In the 1950s and 1960s, the CIA did, in fact, administer drugs such as LSD under Project MKULTRA in an effort to investigate the possibility of “mind control.” Also during the Cold War, Operation Northwoods, a rumored plan by the US Department of Defense to simulate acts of terrorism and blame them on Cuba, really was proposed by high-level officials (though the plan never went into effect). In 1947, space aliens did, in fact, land in Roswell, New Mexico, and the government covered it all up. (Well, maybe not.)

An important clarification: the focus throughout this chapter is on demonstrably false conspiracy theories, such as the various 9/11 conspiracy theories, not ones that are or may be true. The ultimate goal is to explore how public officials might undermine false theories, and true accounts should not be undermined.

Within the set of false conspiracy theories, it is also important to limit the scope to potentially harmful theories. Not all false conspiracy theories are harmful. Consider the false conspiracy theory, held by many younger members of our society, that a secret group of elves, working in a remote location under the leadership of the mysterious “Santa Claus,” makes and distributes presents on Christmas Eve. This theory turns out to be false but is itself instilled through a widespread conspiracy of the powerful—parents—who conceal their roles in the whole affair. (Consider, too, the Easter Bunny and the Tooth Fairy.) Unfortunately, not all conspiracy theories are equally benign.

Conspiracy theories generally attribute to certain agents extraordinary powers: to plan, to control others, to maintain secrets, and so forth. Those who believe that those agents possess such powers are especially unlikely to give respectful attention to debunkers, who, in their eyes, may, after all, be agents or dupes of those responsible for the conspiracy in the first place. Because debunkers are untrustworthy, the simplest governmental technique for dispelling false (and also harmful) beliefs—providing credible information—may fail to work for conspiracy theories. This extra resistance to correction through simple techniques is part of what makes conspiracy theories distinctively worrisome.

A broader point is that conspiracy theorists typically overestimate the competence and discretion of officials and bureaucracies, which are assumed to be capable of devising and carrying out sophisticated secret plans—despite abundant evidence that in open societies, government action does not usually remain secret for very long. Consider all the work that must be done to hide and cover up the government’s role in orchestrating a terrorist attack on its own territory or in arranging to kill political opponents. In a closed society, secrets are far easier 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 disprove in light of available information. But when the press is free, and when checks and balances are in force, government cannot easily hide its conspiracies for long.

These points do not mean that it is impossible, even in free societies, for conspiracy theories to be true; we have seen some counterexamples. 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.

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 it because the god Vulcan revealed it to me in a dream, my belief is unjustified. 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. It is unnecessary to take a 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. A brief review of the possible accounts will be useful for later discussion.

The philosopher 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.10 The basic idea is that many social outcomes, 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 real estate or 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 maxim “Cui bono?”), and for this reason, conspiracy theories have considerable but unwarranted appeal. 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 products of social ­interactions among numerous people.

Popper captures an important feature of some conspiracy theories. They have appeal in light of the attribution of otherwise inexplicable events to intentional action, and of some people’s unwillingness to accept the possibility that significant bad consequences may be a product of invisible-hand mechanisms (such as market forces or evolutionary pressures) or of simple chance rather than of anyone’s plans. A conspiracy theory posits that a social outcome reflects 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 nonarbitrary causal stories. 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. The conspiracy theorists go wrong not by positing intentional actors but by misidentifying them.

A broader point is that part of what makes (unjustified) conspiracy theories unjustified is that those who believe them must also have a kind of spreading distrust of all knowledge-producing institutions, in a way that makes it difficult for them to believe anything at all.11 To believe, for example, that the US government destroyed the World Trade Center and then covered its tracks requires an ever-widening conspiracy theory in which the 9/11 Commission, congressional leaders, the Federal Bureau of Investigation (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 his 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. Why reject so many of the claims and judgments supplied by knowledge-producing institutions while accepting the rest? 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 Duck.”12 Consider in this light the words of Oliver Stone, director of the conspiracy-focused film JFK: “I’ve come to have severe doubts about Columbus, about Washington, about the Civil War being fought over slavery, about World War I, about World War II and the supposed fight against Nazism and Japanese control of resources . . . I don’t even know if I was born or who my parents were.”13

This is not a claim that conspiracy theories are always wrong or unwarranted. We have seen that some such theories are true. But if knowledge-producing institutions are generally trustworthy, in part because they are embedded in an open society with a well-functioning marketplace of ideas and a free flow of information, then conspiracy theories will usually be unjustified. On the other hand, citizens of societies with systematically censored, malfunctioning, biased, or skewed institutions of knowledge—say, people 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 justified, whether they are true or not. (And because of the absence of democratic safeguards, they will more often be true as well.)

Likewise, people living in isolated groups or networks who are exposed only to skewed information will more often hold conspiracy theories that are false but nonetheless justified given their limited information. Most of us have direct or personal knowledge of very few of the facts that we firmly believe. We do not know, from direct personal knowledge, that the Earth is round; or that Mars exists; or that William Shakespeare, Christopher Columbus, and Babe Ruth really lived; or that matter is composed partly of electrons. Most of what we know comes from other people’s statements, beliefs, and actions. When those in isolated groups or social networks accept conspiracy theories, they may be accepting—simply and not unreasonably—everyone else’s beliefs. Even Holocaust deniers might 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 (so long as 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.

These points help to explain a central feature of conspiracy theories, which is that they tend to be extremely resistant to correction, certainly through direct denials or counterspeech by government officials. Conspiracy theorists believe that the agents of the conspiracy have unusual powers, so that apparently contrary evidence can be seen as a product of the conspiracy itself. The self-sealing quality of conspiracy theories creates severe practical problems for those who seek to dispel them, including government. Direct attempts to dispel the theory are often folded into the theory as just one more ploy by powerful machinators to cover their tracks. On this count, the creativity and inventiveness of conspiracy theorists should not be underestimated.14

A denial might even be taken as a confirmation, and the ­evidence mustered on behalf of the denial might be seen as corroborative rather than contradictory. A few years ago, for example, both liberals and conservatives were provided with apparently credible ­information showing that the administration of President George W. Bush was wrong to conclude that Iraq had an active unconventional weapons program. Yet after receiving the accurate information, conservatives became even more likely to believe that Iraq possessed such weapons and was seeking to develop more.15 (Liberals are no less subject to this general effect.)

When someone denies one of your strongest commitments, you might respond by holding it more fiercely. One reason involves your motivations. If you believe something deeply, you might well have a strong emotional commitment to it and hold on to it even more intensely if it is attacked. Another reason is that if you think that you have strong reasons for a belief, a denial might seem corroborative. If you are highly suspicious, the very effort to deny the commitment suggests that it is likely to be true. Why else would people bother to deny it?


Conspiracist Propensities and 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. Perhaps conspiracy theories are a product of 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. But we have seen that in many communities, and even in 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 psychological pathology.

Putting pathology to one side, evidence does suggest the existence of stable differences in people’s propensity to accept conspiracy theories.16 The best predictor of whether people will accept a conspiracy theory appears to be whether they accept other conspiracy theories. Those who accept one such theory (for example, that the FBI killed Martin Luther King Jr.) are especially likely to accept others (for example, that climate change is a hoax). Most striking, researchers have found that “this tendency even extends to beliefs in mutually contradictory conspiracy theories, and to beliefs in fully fictitious conspiracy theories. Thus, those who believe that Princess Diana faked her own death are also more likely to believe that she was murdered; those who believe in ‘real-world conspiracy theories’ (i.e., that John F. Kennedy fell victim to an organized conspiracy) are more likely to believe that there was a conspiracy behind the success of the Red Bull energy drink—a conspiracy theory that was purposely developed for a social psychology study.”17

Some people do show an unusually strong inclination to accept conspiracy theories. Peculiar as it is, the willingness to accept contradictory conspiracy theories is especially suggestive of this inclination, as reflected in the remarkable finding that those people who believe that Osama bin Laden was already dead at the time when US special forces raided his compound in Pakistan are also more likely to believe he is still alive.18 Some people appear to hold a broad view of the world according to which the authorities are engaged in conspiracies; accounts that fit with that view of the world are appealing even if they contradict each other. On this account, “conspiracism [is] a coherent ideology, rather than as a cluster of beliefs in individual theories.”19 In other words, a willingness to believe in conspiracy theories is the master concept, organizing particular beliefs. (As we will shortly see, however, conspiracists are made, not born.)

In fact, there is evidence that those who believe that a particular scientific finding is made up, and actually a product of a conspiracy, are more likely to have the same view about other scientific findings.20 Suppose that certain people believe that the moon landings never happened and were faked by NASA. Those people are especially likely to believe that climate change is a hoax as well. Indeed, conspiracist thinking in areas that have nothing to do with science (reflected, for example, in the view that the FBI was involved in the killing of Martin Luther King Jr.) predicts the rejection of scientific findings as a product of conspiracies. Intriguingly, those who believe in conspiracy theories have been found to be more willing to conspire themselves.21

Is it possible to say more about the characteristics that lead people to accept such theories? We do not have full answers, but research suggests that conspiracist thinking is especially likely to appeal to people who are cynical about politics, who have lower self-esteem, and who are generally defiant of authority.22 Causation works both ways. Those who believe in conspiracy theories become less likely to engage in politics.23

For present purposes, however, the most useful way to understand the pervasiveness of conspiracy theories is to examine how people come to acquire their beliefs. In some domains, people suffer from what Professor Russell Hardin has called a crippled epistemology, in the sense that they know relatively few things, and what they know is wrong.24 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. Conspiracy theorizing often has the same feature. For instance, those who believe that Israel was responsible for the 9/11 attacks, or that the CIA killed President Kennedy, may well be responding quite rationally to the informational signals that they receive.

Consider here the suggestive claim that terrorism is more likely to arise in societies that lack civil rights and civil liberties.25 If this is so, it might be because terrorism is not abstract violence but an extreme form of political protest. When people lack the usual outlets for registering their protest, they resort to violence. A contributing factor is that when civil rights and civil liberties are restricted, little information is available, and the information that comes from government cannot be trusted. In those circumstances, conspiracy theories are more likely to spread, and terrorism is more likely to arise.

Rumors and Speculation. Some conspiracy theories seem to bubble up spontaneously, appearing roughly simultaneously in some or many different social networks. In such cases, they may be a response to specific disturbing events, to general or localized economic or social distress, or to real or apparent injustice. Others are initiated and spread quite intentionally by conspiracy entrepreneurs, who may play a large role in the spread of conspiracy theories, and who profit directly or indirectly from propagating their preferred theories.

One example in the latter category is the author of the Chinese bestseller mentioned earlier. Another is the French author Thierry Meyssan, whose book 9/11: The Big Lie became a bestseller and a sensation for its claim that the destruction at the Pentagon on 9/11 was caused by a missile fired as the opening salvo of a coup d’état by the military-industrial complex rather than by American Airlines Flight 77. (In the context of the 9/11 attacks, there are many other examples.)

Some conspiracy entrepreneurs are entirely sincere; others are interested in money or fame, or in achieving some general social goal. In the context of the AIDS virus, a diverse set of people have initiated rumors, many involving conspiracies, and, in view of the confusion and fear surrounding that virus, several of those rumors spread widely.26 Even for conspiracy theories ventured by conspiracy entrepreneurs, the key question is why some theories take hold, while many more vanish into obscurity. There are plausible answers to that question, but a great deal may depend on random and unpredictable factors, including who says what to whom, and exactly when.27 The success or failure of conspiracy theories, like that of rumors in general, is far from preordained.

Whenever a crisis or tragedy occurs, 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, or why an economy suddenly ran into terrible trouble. 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, or because the speculation is in some sense gratifying or fits well with other deeply rooted beliefs, or because the absence of an explanation is disturbing. Terrible events produce outrage, and when people are outraged, they are all the more likely to seek causes that justify their emotional states, and also to attribute those events to intentional action.

It is important to see that preexisting inclinations and beliefs are key to the success or failure of conspiracy theories. To the extent that some people show a propensity to believe such theories, they will be drawn to them even on the basis of highly speculative accounts. Some people would find it impossibly jarring to think that the FBI was behind the assassination of Martin Luther King; that thought would unsettle too many of their other judgments. Others would find those other judgments supported strongly, even confirmed, by the suggestion that the FBI was responsible. For most Americans, a claim that the US government attacked its own citizens, and thus was responsible for a terrorist attack, would make it impossible to hold on to 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 many beliefs, and accepting or rejecting a conspiracy theory will often depend on which of the two brings equilibrium. Some beliefs are also motivated, in the sense that people are pleased to hold them or displeased to reject them. 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 as well as the antecedent knowledge of those who hear the claim.

These are points about individual judgments, bracketing social influences. But after some devastating event has occurred, those influences are crucial. 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 assassinated President Kennedy on his own, or how the AIDS crisis began, or whether a tragic death in an apparent airplane accident was truly accidental, or what caused the economic collapse of 2008, or the precise background of the explosions at the Boston Marathon in 2013? Inevitably, people must rely on the beliefs of others. Some of us will require a great deal of evidence in order to accept a conspiracy theory, while others will require much less. People will therefore have different thresholds for accepting or rejecting such a theory. One way to meet a relevant threshold is to supply direct or indirect evidence. Another is simply to show that some, many, or most (trusted) people accept or reject the theory. These are the appropriate circumstances for social cascades, both informational and reputational.

Conspiracy Cascades, 1: The Role of Information. To see how informational cascades work,28 imagine that a group is trying to assign responsibility for some loss of life. Assume that the group’s 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 Andrews’s account if she agrees independently with him. But if she does not have a lot of private information, and really does not know what happened, she might well be swayed by his judgment and agree that the event was a product of a conspiracy.

Now turn to a third person, Charleton. Suppose that both Andrews and Barnes have embraced the conspiracy theory, but that Charleton’s view, based on limited information, is that they are probably wrong. Because his own information is limited, Charleton might well ignore what he knows and follow Andrews and Barnes. It is likely, after all, that both Andrews and Barnes have evidence for their conclusions, 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 believe that Andrews and Barnes are being foolish. But if he lacks those grounds, he will go along with them.

Now suppose that Charleton is speaking in response to what Andrews and Barnes said, not on the basis of his own information, and also that subsequent group members David and Esther 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 not decisive). David and Esther might ask, “How could Andrews, Barnes, and Charleton all be wrong?” This will happen even if Andrews initially speculated in a way that does not fit the facts—especially if people discount, as they tend to,29 the possibility that the shared belief is, for Barnes and Charleton, based not on independent information but merely on a reaction to Andrews’s speculation. In such cases, the initial speculation starts a process by which a lot of people are led to participate in a cascade, accepting a conspiracy theory built upon a most fragile foundation.

Of course, the example is stylized and unrealistic. Conspiracy cascades arise through more complex processes in which people’s diverse thresholds are important. In the standard pattern, the conspiracy theory is initially accepted by people with low thresholds for its acceptance; as we have seen, some people do have such thresholds. Perhaps the theory will be limited to such people. But sometimes the informational pressure, based on the shared judgments of those people, builds to the point where many other people, with somewhat higher thresholds, begin to accept the theory too. As those with higher thresholds accept the theory, the pressure continues to build, to the point where a large number of people end up accepting it. As we shall see, this outcome is especially likely in close-knit or isolated social networks.

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 or to avoid disfavor. Reputational pressures help account for conspiracy theories, and they feed conspiracy cascades.

In a reputational cascade, people think that they know what is right, but they go along with the crowd in order to maintain the approval of others. Suppose that Albert suggests that the United States was responsible for some terrible event in the world. Barbara concurs with Albert, not because she actually thinks that Albert is right (she might even think that he is a bit nuts) but because she does not want him to view her as some kind of fool or dupe. And if Albert and Barbara blame the United States for that terrible event, Cynthia might not contradict them publicly and might even appear to share their judgment—not because she believes that they are correct but because she does not want to face their hostility or lose their good opinion of her.

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 carries information; that view might be right. But even if David has reason to disagree, he might not want to take them on publicly. His silence will help build the informational and reputational pressure on those who follow.

It seems clear that reputational pressures play a large role in the adoption and dissemination of conspiracy theories, certainly among small, close-knit groups and social networks but also more generally. If everyone in your religious community believes that certain people are engaged in a conspiracy against the community, you might silence any private doubts that you might have. In some times and places, doubting a conspiracy theory, or even failing to endorse it, can be literally dangerous, in the sense that doubters are ostracized or worse. Some conspiracy theories are able to persist only because people silence themselves. Dissent is an indispensable corrective, but it does not occur.

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 sense that it comes readily to mind. In the context of many risks, such as those associated with terrorism, crime, economic catastrophe, and environmental disasters, a particular event initiates a cascade. It works as a trigger, an icon, or a symbol justifying public concern, whether or not that concern is warranted. 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, making people fearful of risks even if there is no objective basis for the fear.

Conspiracy theories can spread through the same mechanisms. A terrible event becomes “available,” in the sense that everyone knows about it, and conspiracy theories are invoked both to explain it and to use it as a symbol for broader social forces. 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 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.

Conspiracy Cascades, 4: The Role of Emotions. Thus far, the account has been largely emotion-free and cognitive; conspiracy theories circulate in the same way that other beliefs circulate, as people give weight to the views of others and attend to their own reputations. But it is clear that emotions, and not merely information, play a large role in the circulation of rumors of all kinds. Many rumors persist and spread because they serve to justify or rationalize an antecedent emotional state produced by some landmark event, such as a disaster or a war. When people are especially angry or fearful, they may be more likely to focus on particular sorts of rumors and spread them to others. And when rumors trigger intense feelings, they are far more likely to be circulated.

Experimental evidence strongly supports this speculation in the analogous context of so-called urban legends,30 involving, for example, a decapitated motorcycle rider, a rat in a soda bottle, or a can of cat food mislabeled as tuna. When urban legends trigger strong emotions (such as disgust), people are more likely to pass them along. On the internet, emotionally gripping tall tales are especially likely to proliferate. In the marketplace of ideas, a form of “emotional selection” plays a significant role, and it helps to explain such diverse phenomena as moral panics about deviant behavior and media attention to relatively rare sources of risk such as road rage and the flesh-eating bacterial infection known as necrotizing fasciitis. A particular problem involves “emotional snowballing”: runaway selection for emotional content rather than for information.

The implications for conspiracy theories should not be obscure. When an awful event has occurred, acceptance of such theories may justify or rationalize the emotional state produced by that event; consider conspiracy theories in response to political assassinations or terrorist attacks. Such theories typically involve accounts, or rumors, that create intense emotions such as indignation—thus promoting a kind of emotional selection that will spread beliefs from one person to another. Of course, evidence matters, and so long as there is some kind of process for meeting falsehoods with truth, mistaken beliefs can be corrected in principle. But sometimes the conditions for corrections are not present; or, even if they are pre­s­ent, people are strongly motivated to disregard them.

Group Polarization. There are clear links between cascades and the well-established phenomenon of group polarization, by which members of a deliberating group typically end up taking a more extreme position in the same direction as their inclinations before deliberation began.31 Group polarization has been found in hundreds of studies involving over a dozen countries. Belief in conspiracy theories is often fueled by group polarization.

Here is an example of how group polarization works. A few years ago, I participated in some studies designed to shed light on how people’s political beliefs are formed.32 My coauthors and I assembled a number of people in Colorado into two sets of groups. Half of them consisted only of liberals; the other half consisted only of conservatives. We asked the participants to discuss three issues: climate change, affirmative action, and civil unions for same-sex couples. We also asked them to state their opinions on each topic at three stages. The first occurred before they started to talk, when we recorded their views privately and anonymously. In the second stage, we asked them to discuss the issues with one another and then to reach a kind of group verdict. In the final stage, we asked people to record their views after discussion, privately and anonymously.

Our findings were simple. On all three issues, both liberals and conservatives became more unified and more extreme after talking only to one another—not merely in their public verdicts but also in their private, anonymous views. Group discussions made conservatives more skeptical of climate change and more hostile to affirmative action and same-sex unions, while liberals showed the opposite pattern. Before discussion, both groups showed far more diversity than they did afterward, and the individuals in the liberal groups were not so very far apart from those in the conservative groups. After discussion, the two sets of groups became much more divided. This is group polarization in action.

Another study finds that that those who disapprove of the United States and are suspicious of its intentions will increase their disapproval and suspicion if they talk to one another. After speaking together about America and its foreign aid policy, citizens of France came to distrust the United States significantly more.33 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 only or mostly with one another, will end up with a greater commitment to that belief.

A striking result of group polarization is that, as in our Colorado study, different groups may end up with radically different attitudes toward conspiracy theories in general and in particular. Speaking with like-minded others, some people may come to find such a theory irresistible. Others may come to find it preposterous.

Group polarization occurs for reasons that closely parallel those that explain cascades. Information plays a large role. In any group having some initial inclination, the arguments offered by most people will inevitably be skewed in favor of that very inclination. If, for example, most people in the group start out believing that Wall Street conspired to create an economic collapse, then everyone in the group will hear a lot of arguments in support of that position, and not so many to the contrary. As a result of hearing the various arguments, people will be hardened in their original belief and are likely to be led toward a more extreme view in line with what group members initially thought. Reputation matters too. People usually want to be perceived favorably by other group members. Once they hear what others believe, some will adjust their positions in the direction of the dominant position.

For purposes of understanding how conspiracy theories spread, it is especially important to see that group polarization is particularly likely, and particularly pronounced, when people have a shared sense of identity and are connected by bonds of solidarity. Social networks matter greatly, and tightly connected networks are more likely to subscribe to conspiracy theories. These are circumstances in which arguments by outsiders, unconnected with the group, will lack much credibility and fail to have much effect in reducing polarization. In such circumstances, direct government rebuttals of the reigning conspiracy theory are especially likely to prove ineffective.

Selection Effects. A crippled epistemology can arise not only from informational and reputational dynamics but also from self-selection of members into and out of groups with extreme views. Once cascades arise or polarization occurs, and the group’s view begins to move in a certain direction, skeptics and partial believers 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. By self-selection, the remaining members will display more fanaticism.

Group members may segregate themselves in order to protect their beliefs from challenges by outsiders. Group leaders may enforce such segregation in order to insulate the rank and file from information or arguments that would undermine the leaders’ hold on the group. Even if contrary information and arguments are in some literal sense heard, they will be ridiculed and made a subject of contempt—and, if at all possible, used as further confirmation of the conspiracy theory. As a result, group polarization will intensify.

Members of isolated groups sometimes display a kind of paranoid cognition and become increasingly suspicious of others or of the larger society, falling into a “sinister attribution error.”34 This error occurs when people mistakenly feel that they are under pervasive scrutiny, attribute personalized motivations, and greatly overestimate the amount of attention they actually receive. (The last is an aggravated version of a general human tendency known as the spotlight effect.)35 Benign actions that happen to disadvantage the group are taken as purposeful plots intended to harm. Although these conditions resemble individual-level pathologies, they need not be. On the contrary, they arise from the social and informational structure of the group, and in the circumstances of interest here, are not usefully understood as a form of mental illness.


What can government do about conspiracy theories? And among the things it can do, what should it do? Simply in order to understand the options (without endorsing any of them), imagine a series of possible responses.

1. Government might ban conspiracy theories.

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 hire or work with credible agents in the private sector to engage in counterspeech.

Each instrument has a distinctive set of potential effects, or costs and benefits, and each will have a place under imaginable conditions. Under current free-speech law, of course, responses 1 and 2 are likely to be unconstitutional, and in a free society, censorship of any kind should be used, if at all, only under the most extraordinarily unusual conditions (for example, to prevent imminent violence).

It is also quite possible that government should stand to one side. Private organizations can and do work hard to respond to false conspiracy theories. An example is the internet site, which researches rumors and conspiracy theories and reports on their truth or falsity. For those concerned about the proliferation of conspiracy theorizing on the internet, this site provides a reliable and helpful reality check. It would be easy to find numerous similar ventures, small and large, in this vein, for the internet provides not only a mechanism by which to spread conspiracy theories but also a range of corrective tools. The more general point is that in free societies, false conspiracy theories are generally debunked by private citizens and institutions far more than by public officials.

Because the cost of spreading information is low, it is easy for private monitors to rebut false conspiracy theories. In just a few seconds, people can find a credible rebuttal of a conspiracy theory or produce a rebuttal themselves. At the same time, that very reduction in information costs makes it easier for conspiracy theorists to generate and spread their theories in the first place. The overall effect of new technology is unclear, as is the ability of private monitors to correct conspiracy theories. In part because this is so, an official response may be important or even essential, at least in some cases.

The first-line response to conspiracy theories is to maintain a free and open society. In such a society, those who might be tempted to believe such theories are exposed to evidence and corrections, and they are unlikely to distrust all knowledge-creating institutions. But we have seen that even in open societies, conspiracy theories can have some traction. Far more important, open societies may have a strong interest in debunking such theories when they arise, and threaten to cause harm, in closed societies. In the most serious cases, those who spread conspiracy theories, and those who receive them, are more likely to cause violence as a result.


One line of thinking denies that conspiracy theories matter. There are several possible reasons to think that they may not, and for the vast majority of conspiracy theories, these reasons seem convincing. First, conspiracy theories may be held by only a tiny fraction of the population. Perhaps only a handful of kooks believe that US government officials had any kind of role in the events of 9/11. Second, even if a particular conspiracy theory is widespread, 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, such as a belief in space aliens or UFOs, and that do not form a premise for action. Perhaps those who seem to accept conspiracy theories have “soft” beliefs, in a way that generally leads them to keep quiet and rarely act on what they tend to think.

At the same time, there is ample evidence that some conspiracy theories are not at all confined to small segments of the population, and that, at least when they are widely held, they may not be innocuous. According to a 2002 Gallup Poll conducted in nine Islamic countries, 61 percent of those surveyed thought that Muslims had nothing to do with the attacks of September 11, 2001. An anonymous State Department official stated that “a great deal of harm can result ‘when people believe these lies and 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.’”36 At various points in history, many members of some racial and religious groups have believed, falsely, that other groups were plotting against them, and those beliefs have not always been harmless.

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 harm, as in the 1995 truck bombing of the Alfred P. Murrah Federal Building in Oklahoma City. Convicted perpetrators Timothy McVeigh, Terry Nichols, and Michael Fortier shared a set of conspiratorial beliefs about the federal government. Many others who shared their beliefs did not act on them, but those three people did, with terrifying consequences: 168 people were killed and 500 injured, making this the deadliest terrorist attack on US soil until September 11, 2001.

In cases of this sort, the conspiracy theory itself supports violent action on the part of its believers; conspiracy theorizing leads to an actual conspiracy. (Recall that people who are prone to conspiring are especially likely to accept conspiracy theories.) Within a network of members who believe that the federal government is a hostile and morally repellent organization that is taking over the country, akin to a foreign invader, armed resistance might seem a sensible course, at least to some.


Imagine a situation in which a particular conspiracy theory is becoming widespread. The government faces two recurring dilemmas. First, should it ignore or rebut the theory? Second, should it (1) address the supply side of conspiracy theorizing by attempting to convince its purveyors that they are wrong, (2) address the demand side by attempting to immunize audiences from the theory’s effects, or (3) do both (if resource constraints permit)?


The first dilemma is that either ignoring or rebutting a conspiracy theory has its own risks and costs. On the one hand, disregarding the theory allows its proponents to draw ominous inferences from the government’s silence. On the other hand, if the theory stands unrebutted, people may pay less attention to it. The government’s silence might suggest that the theory is too ludicrous to warrant a rebuttal—and has the advantage of not encouraging people to focus on it. These points counsel in favor of silence for the vast majority of conspiracy theories, which are roundly and rightly ignored and fall from their own weight. But another possibility is that the government is silent because it cannot offer convincing evidence to the contrary. Conspiracy theorists will, of course, contend that “no comment” is a concession of some kind.

At the same time, the very effort to rebut the theory may legitimate it. People may infer from the government’s rebuttal that it considers the conspiracy theory to be plausible and fears that many people will be persuaded. The very act of rebuttal also focuses the audience on the theory in a way that may increase its salience. Those who might reject the theory, or not give it much thought, may take the rebuttal as a reason to think about it and perhaps consider it seriously.

Some members of the audience may also infer that many other members of the audience must believe the conspiracy theory, or the government would not be taking the trouble to rebut it. Consider circumstances of “pluralistic ignorance,” in which citizens are unsure what other citizens believe. If the government’s rebuttal is a signal that other citizens accept the conspiracy theory, it may make the theory more plausible. The perverse result of the rebuttal may then be to increase the number of believers. We have also seen that corrections can backfire. People may be motivated to intensify their commitment to their convictions once that commitment is placed under strain.

How should government cope with this dilemma? There is no general or obvious answer. Reasonable officials may adopt a wait-and-see strategy: ignore the conspiracy theory unless it reaches some ill-defined threshold of widespread popularity and then rebut. But waiting too long can also be harmful, at least if there is a significant chance that the theory will gain sufficient traction to cause harm. Conspiracy theories sometimes spread by rumor, and empirical study of rumor psychology shows that “[t]o curb rumors, one must act quickly . . . [A]s a rumor circulates, it tends to evolve into a more believable version and therefore becomes harder to contain. [Also], the more times people hear the rumor, the more likely they are to believe it.”37 In particular, some studies show that when officials or firms are asked about rumors, a response of “no comment” is affirmatively harmful; audiences tend to suspect a cover-up. When asked explicitly, officials should deny the rumor by pointing to specifics. Counterintuitively, a blanket denial may be inferior to one that incorporates, and thus mentions, the rumor itself.38


Should the governmental response be addressed to the suppliers of conspiracy theories, with the goal of persuading them, or should it be addressed to the mass audience, with the goal of inoculating people against pernicious theories?

Perhaps the best approach is to straddle the two audiences with a single response or simply to provide multiple responses. If there are resource constraints, government may face a choice about where to place its emphasis. Apart from resource constraints, there may be trade-offs across these strategies. The very arguments that are most convincing to the mass audience may be least convincing to the conspiracy theorists, and vice versa.

We have seen that those who embrace a conspiracy theory are especially resistant to contrary evidence offered by the government, because the government’s rebuttal might be folded into the conspiracy theory itself. After 9/11, one set 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 subsequent 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.)39 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.40

Because of these difficulties, direct responses to the suppliers of conspiracy theories might be dismissed as exercises in futility. Those with strong commitments often engage in “biased assimilation” of evidence,41 and conspiracy theorists are likely to be especially biased assimilators. In the context of the assassination of President Kennedy, for example, biased assimilation has been explicitly observed, with balanced information leading believers to be more, not less, committed to their conspiracy theory.42

Sometimes officials choose to frame their responses to the 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.”43 Likewise, when public officials issued a fact sheet to disprove the theory that the World Trade Center was brought down by a controlled demolition, one official stated, “We 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.”44


Rather than taking the continued existence of the hard core as a constraint, and addressing itself solely to the mass audience, government might take steps to break up the tight cognitive clusters of conspiracist theories, arguments, and rhetoric that are produced by the hard core and that reinforce it in turn. A potential approach (growing directly out of the account here of how such theories spread) is cognitive infiltration of extremist groups. As used here, this admittedly provocative term does not mean 1960s-style infiltration with a view to surveillance and collecting information, possibly for use in future prosecutions. Rather, it means that government efforts might succeed in weakening or even breaking up the ideological and epistemological complexes that constitute these networks and groups. Of course, any such efforts should be consistent with domestic law, including constitutional protections of free speech and personal privacy. The focus of the discussion is on situations involving serious security risks, above all risks of terrorism, that arise from conspiracy theories in foreign countries.

How might this tactic work? Recall that extremist networks and groups, including those 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. Perhaps the generation of ever-more-extreme views within these groups can be dampened or reversed by the introduction of cognitive diversity. Government might introduce such diversity—needless to say, only under circumstances in which there is a compelling and legitimate need to respond to the conspiracy theory, as, for example, to reduce a threat of violence from potential terrorists in another nation. Under this approach, government agents and their allies might enter foreign 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 action, political or otherwise. Because conspiracy theories are self-sealing, government agents face serious challenges. But there are several possible routes.

In one variant, government agents would openly proclaim—or at least make no effort to conceal—their institutional affiliations. A 2007 newspaper story reported that Arabic-speaking Muslim officials from the State Department had participated in dialogues in radical Islamist chat rooms and on websites in order to calm the situation by offering arguments not usually heard among the groups that post messages on those sites, with some success.45 In another variant, government officials would participate anonymously or even with false identities. Each approach has distinct costs and benefits; the second raises ethical concerns and is riskier, but it might bring higher returns. Where government officials participate openly, hard-core members of the relevant networks, communities, and conspiracy-minded organizations may entirely discount what the officials say, right from the beginning. Because conspiracy theorists are likely to approach evidence and arguments in a biased way, they are not likely to respond well to the claims of public officials. Those claims might be received as self-refuting; conspiracists who hear them might well respond with the dismissive phrase “consider the source.”

The advantage of anonymous participation, and of working with agents, is that such dismissals are less likely. A great deal of work suggests the potential credibility of “surprising validators”: people who are not expected to take a particular position and are persuasive for that reason.46 If, for example, a prominent conservative, known to be a skeptic about environmentalism, says that climate change is real and needs to be addressed, some people might well be moved. So, too, with conspiracy theories. If a person who is credible in the relevant community—say, someone who is known not to be friendly to the United States—says plainly that a conspiracy theory about America is false, people may listen, and waters might be calmed.

The problems with anonymous participation and hidden agents involve both ethics and disclosure. Outside of unusual ­circumstances (above all, genuine national security threats), public officials should not conceal their identity. And if the tactic becomes known, the ­theory may become further entrenched, and any real member of the relevant groups who raises doubts may be suspected of having ­government connections. The two forms of cognitive infiltration offer evidently different risk-reward mixes.

There is a similar trade-off along another dimension: whether the efforts should occur in the real world or 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 plan conspiracies) formulate their views through real-space informational networks rather than virtual networks. Infiltration of any kind poses risks, but they are generally greater for real-world infiltration, where the agent is exposed to more serious harms.

There are also hard questions about how, exactly, to introduce cognitive diversity into a group of people strongly committed to a conspiracy theory. Even if the infiltrators are generally ­credible, they are unlikely to be effective if they simply proclaim that the theory “is wrong” or even if they introduce evidence suggesting that the widely held view is mistaken. A growing body of research indicates that if the goal is to dislodge a particular belief of an individual or group, the best approach is to begin by affirming other ­beliefs—or at least the competence and character—of that individual or group.47 For example, those who have strong views about capital punishment or abortion are far more likely to listen to counter­arguments if those who make such counterarguments take significant steps to affirm those with whom they are engaging. The general conclusion is that cognitive diversity, as such, is hardly enough; it is necessary also to insure a degree of receptivity toward those with divergent views.


Some people have a propensity to accept conspiracy theories, as reflected in the finding that people who tend to believe one are likely to believe another, even if the two are in direct contradiction. Many people who accept conspiracy theories suffer from a crippled epistemology. Their beliefs are a function of what they hear. For that reason, isolated social networks can be a breeding ground for conspiracy theories.

In some cases, those theories help to fuel violence. To reduce that risk, it is indispensable to understand how those theories arise and how rational people can come to hold them even if they are palpably false. Conspiracy theories are, of course, an extreme case, but an understanding of the mechanisms that lie behind them helps to shed light on the formation of political beliefs in general and on why some of those beliefs go wrong.

About The Author

Photograph by Phil Farnsworth

Cass R. Sunstein is the nation’s most-cited legal scholar who, for the past fifteen years, has been at the forefront of behavioral economics. From 2009 to 2012, he served as the administrator of the White House Office of Information and Regulatory Affairs. Since that time, he has served in the US government in multiple capacities and worked with the United Nations and the World Health Organization, where he chaired the Technical Advisory Group on Behavioral Insights and Sciences for Health during the COVID-19 pandemic. He is the Robert Walmsley University Professor at Harvard Law School. His book Nudge, coauthored with Richard Thaler, was a national bestseller. In 2018, he was the recipient of the Holberg Prize from the government of Norway, sometimes described as equivalent of the Nobel Prize for law and the humanities. He lives in Boston and Washington, DC, with his wife, children, and labrador retrievers.

Product Details

  • Publisher: Simon & Schuster (June 7, 2016)
  • Length: 288 pages
  • ISBN13: 9781476726632

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“Glenn Beck has described Cass Sunstein as ‘the most dangerous man in America,’ but the 11 essays collected in ‘Conspiracy Theories and Other Dangerous Ideas’ actually reveal him to be a pretty reasonable guy. He is often provocative but never extreme, and the foaming at the mouth he induces says more about our polarized politics than it does about his ideas…Sunstein is an advocate for what works and a skeptic of grand ideologies that sound good on paper but then wreak havoc in the real world…Throughout the 11 essays in this book, Sunstein is a clear-eyed guide through some of the thornier issues of our day.”

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