Black swan events are highly improbable events that have great, negative impact. Conspiracy theories are coping mechanisms for black swan events: They try to explain them. However, conspiracy theories are epistemologically defective because they mistake the very low probability of black swan events as impossibility, and thus, a conspiracy as the only possible explanation.

A conspiracy theory is the belief that the common explanation for some event or some state of affairs is not true, and that, in reality, some actors (individuals or organizations) are responsible for that event or state of affairs. In addition, the common explanation that is supposedly false is believed to be manufactured by those actors in order to deceive the public^{1 2}.

From an epistemological point of view, conspiracy theories are irrational, since they constitute a form of unjustified belief. The belief in a conspiracy theory is usually (there might be empirical exceptions) simply the belief that the common explanation is false, and that belief is improperly justified by an appeal to incredulity. Of course, believing that one explanation is false does not in any way provide support for an alternative (conspiratorial) explanation.

Conspiracy theories are irrational because of their flawed epistemology, not because of their truth status. A conspiracy theory might very well turn out to be ultimately true, but it is still irrational, because its justification mechanism is defective. Such a constellation is sometimes referred to as a Gettier case³, and, in the context of conspiracy theories, defective justification is sometimes described as „crippled epistemology“⁴.

Not impossible, merely improbable: Black swans.

Conspiracy theories proliferate because they offer explanatory completeness⁵: Events and states of affairs that are complex, sometimes random and oftentimes shocking can seemingly be fully explained with conspiracy theories. From this functional point of view, conspiracy theories are a coping mechanism. Conspiracy theories as a coping mechanism become especially important in contexts after a highly improbable event, a so-called black swan event, has taken place.

Probability and black swan events

Humans are bad at dealing with probabilities. Intuitively, we are prone to thinking about the world in deterministic terms: Something either is or isn’t. Accordingly, we like to think that things are either caused by something or they are not. From an ontological point of view, such an attitude makes sense. If we accept the idea of realism, then there is indeed a reality where things either are or aren’t. However, as inhabitants of that reality, we do not have an objective outside perspective to assess it. Instead, the next best and only thing we can do is to try to describe and understand reality in terms of probabilities.

In and of themselves, probabilities are uncontroversial. For example, no one would dispute that the probability of rolling a 4 on a fair, six-sided die is about 1/6. When when it comes to thinking and acting based on probabilities, though, we quickly run into problems. Our trouble with probabilities and probabilistic thinking is obvious when dealing with probabilities of future events and outcomes. Say, for example, that you accept that the probability for rolling a 4 is 1/6. What, exactly, does that probability tell you about the future? Of course, you know that when you actually roll the die, you will either roll a 4 or not, but you will not roll 1/6 of a 4. Does that mean that the probability of 1/6 is meaningless? But that, of course, doesn’t sound right. Can you instead just use a heuristic? For example, can you assume that you would end up with a 4 1/6 of the time if you were to roll the die infinitely often? Unfortunately, such a „frequentist“ idea of probability does not really work all that well^{6 7}. A general way to understand probabilities is that probabilities express the degree of uncertainty surrounding our beliefs⁸. This means that, by declaring that the probability of rolling a 4 is 1/6, you are expressing the amount of uncertainty surrounding your belief that the outcome will be 4.

The smaller the probabilities we deal with are, the greater the uncertainty of the events and outcomes in question. In principle, the nature of small probabilities is exactly the same as the nature of large probabilities. Our sense of probability, however, is very shaky to begin with, and when we have to deal with very small probabilities, it routinely fails us. For the most part, that is not a big problem, because often, treating small probabilities as if they were inexistent is an efficient way of going about things. For example, every time we drive a car, there is a small probability that we will be involved in an accident. Trying to manage those small probabilities on a daily basis is cognitively exhausting. Instead, we simply ignore them and behave as if the probability of an accident were zero.

Ignoring small probabilities is fine most of the time. But sometimes, events and outcomes with very low probabilities actually do happen – and when they do, we deal with them in an irrational manner. This is especially true when those events are events with some form of great impact. Such low-probability high-impact events are sometimes referred to as black swan events^{9 10}. Black swan events are events that are very improbable and, therefore, very rare. Furthermore, they are consequential in that they have some form of large impact. A third important property of black swan events is hindsight bias¹¹: After a black swan event has occurred, we tend to rationalize post hoc that the event was actually explainable and predictable when, in fact, it was not.

Black swan events are manifestations of the limitations of our limited handling capabilities of probabilities. As such, they are also important in the context of conspiracy theories: Conspiracy theories as coping mechanisms can be a form of post hoc rationalization of black swan events.

Conspiratorial thinking as a coping mechanism for black swan events

Many conspiracy theories are concerned with events that can be described as black swan events. For example, the idea that the common explanation for the 9/11 terror attacks is false and that the conspirators have created that falsehood is a conspiracy theory (or, more precisely: a family of conspiracy theories) that try to explain the terror attacks of the September 11, 2001 in the United States. The 9/11 terror attack is a good example of a black swan event: The probability for such an attack to succeed was, arguably, very small, given that it was carried out by what can be described as a ragtag group of terrorists. Furthermore, some specific outcomes within the attack, such as the way the three World Trade Center towers collapsed, was, perhaps, also rather improbable (this is true primarily for WTC7, which was not hit by a plane). Second, the 9/11 terror attacks most certainly had tremendous impact, in terms of the immediate death toll as well as in terms of the consequences in the United States‘ domestic and foreign policy¹².

Conspiracy theories such as the 9/11 conspiracy theories, then, tackle black swan events. However, as coping mechanisms for black swan events, they differ from the regular are not simply a form of post hoc rationalization in the form of a hindsight bias. The hindsight bias after black swan events is the tendency to interpret the black swan event as en event that was not a black swan event. This means that, in the wake of a black swan event, we tend to irrationally believe that the event was more probable than it actually was.

In contrast, conspiracy theories do not try to reinterpret the black swan event’s actual low probability as a high probability. Instead, they do the opposite: They reframe the black swan event’s low probability as impossibility. Within a conspiracy theory, the fact that an event is highly improbable is misunderstood as „proof“ (i.e., justification for the belief) that the event could not have taken place. Therefore, the defective reasoning goes, the event in question must have

The lack of probabilism within conspiratorial epistemology lies at the heart of the problem described above: Within conspiracy theories, there is a sincere belief that the common explanation is impossible, and therefore, an alternative, conspiratorial explanation must be true. But this is fundamentally mistaken: Black swan events are highly improbable, but very low probability does not mean impossibility.

Conclusion: The need for probabilistic thinking

The subset of conspiracy theories that function as coping mechanisms for black swan events are all too understandable. After all, black swan events are events that shock us one way or the other precisely because they are highly improbable. However, conspiracy theories are epistemically irrational because they make a crucial mistake: Very low probabilities are treated as indicators of impossibility. If an event, as accounted for in the common explanation, is believed to be impossible, then, it follows that the only possible explanation is a conspiracy.

The lack of probabilism as a source of conspiracy theories means that „debunking“ conspiracy theories is bound to have very limited success; not least because „debuking“ is often simply not possible due to the epistemic nature of conspiracy theories. Instead, a greater appreciation of probabilistic thinking is, possibly and hopefully, a more effective route of reducing conspiratorial thinking.

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