How to tell the difference between a conspiracy theory and a theory about a conspiracy

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Part 2/5: A theory of theories

Unlike a scientific theory, which is subject to the scientific method, a conspiracy theory is subject to an investigative procedure, which seeks to determine the extent to which an evidence base supporting an allegation is strong enough to justify a conviction. An investigative procedure describes the gathering and analysis of information with the purpose of enabling a hypothetical deliberative agreement among a group of well informed, impartial and reasonable human beings based entirely on the body of evidence available. It follows that a “theory” in this sense consists of one or more theory-specific conclusions which are supported by an evidence base which is composed of data points (facts, statistics, observations, etc.) and premises. Premises represent truth-claims with varying levels of confidence, ranging from speculative claims (conjectures, assumptions, hypotheses, etc.) over interpretations of data points (e.g. in terms of correlations, causal relationships, natural laws, etc.) to factual statements and logical conclusions. Data points and premises are based on sources which can be analyzed for their credibility in order to justify higher levels of confidence. In an investigative procedure a minimum level of credibility/confidence is required for pieces of evidence to be admissible.

In contrast to the term “conspiracy theory,” the expression “theory about a conspiracy” shall be used henceforth to describe a “strong” theory, one which has passed diligent scrutiny and is substantially more likely to be true. But how can we tell the difference between a “conspiracy theory” from a “theory about a conspiracy?” What differentiates a “strong” theory from a “weak” theory? The quality of a theory depends on at least three factors: 1) its logical coherence (taking into account the possibility of common cognitive biases), 2) its openness to improvement/refutation (drawing on Karl Popper’s criterion of falsifiability, sufficiently credible pieces of new evidence result in a corresponding improvement of the theory, including its refutation), and 3) the strength of its evidence base. Accordingly, theories can be considered strong when they exhibit all of the following characteristics (and weak to the extent that one or more of these criteria is not being met): they are logically coherent, open to improvement/refutation, and based on a strong evidence base. The strength of an evidence base can be determined by the extent by which it meets all of the following criteria:

  • Relevance and significance: This criterion suggests that in general, each piece of evidence provided in support of a theory should make a substantial contribution to the theory’s strength. Moreover, pieces of evidence should receive visibility and recognition in proportion to their relative importance or weight. Marginally and tangentially supportive pieces of information may be left out for the sake of clarity.
  • Factuality and rationality/scientificality: The criterion of factuality and rationality/scientificality requires that pieces of evidence are consistent with facts and other well-established rational/scientific findings. The strength of a theory is drastically reduced when pieces of evidence are contradicted by independent fact checking efforts or well established rational/scientific findings. In this context, we can observe that conspiracy theories are often used to deny established scientific findings that might contradict politically preferred premises. The strength of a theory is further increased when a relatively high proportion of independent subject matter experts come to a high level of agreement. In its fifth assessment report, the IPCC defined confidence as a combination of the level of expert agreement on the one hand (low, medium, high) and the robustness of available evidence (low, medium, robust) on the other. While it may be possible to corrupt individual scientists to serve as biased paid experts, a whole international scientific community cannot be corrupted (or manipulated) that easily. Finally, factuality and rationality/scientificality demand minimum speculation: The total evidence base should as much as possible rely on factual and rational/scientific truth-claims and only if necessary on subjective and speculative truth-claims. This criterion also suggests that pieces of unconscious speculation — premises that are mistakenly taken for granted without sufficient justification — need to be identified and discounted as such.
  • Credibility and reliability. In order to assess the credibility and reliability of a source, the practice of source criticism that represents part of the historical method offers useful heuristics. A general rule suggests to always analyse the credibility of each source, (allowing for establishing a background probability), as well as of each piece of evidence provided by the source separately. Credibility presupposes reliability: the source should be authentic, unaltered and not be taken out of context. Numerous additional heuristics for establishing credibility were formulated at the end of the 20th century by Olden-Jørgensen (1998) and Thurén (1997):
  • “Human sources may be relics such as a fingerprint; or narratives such as a statement or a letter. Relics are more credible sources than narratives.
  • Any given source may be forged or corrupted. Strong indications of the originality of the source increase its reliability.
  • The closer a source is to the event which it purports to describe, the more one can trust it to give an accurate historical description of what actually happened.
  • An eyewitness is more reliable than testimony at second hand, which is more reliable than hearsay at further remove, and so on.
  • If a number of independent sources contain the same message, the credibility of the message is strongly increased.
  • The tendency of a source is its motivation for providing some kind of bias. Tendencies should be minimized or supplemented with opposite motivations.
  • If it can be demonstrated that the witness or source has no direct interest in creating bias then the credibility of the message is increased.”

In today’s age of digital and social media, we may add:

Having established the difference between weak and strong theories, we can now ask ourselves two sets of questions with regard to a given theory:

  1. How high is my own (or others’) level of confidence in the theory?
  2. How strong is the theory?

The answers to these questions allow us to determine to what extent our own (and others’) confidence or skepticism regarding a given theory is reasonable and justified. Different levels of confidence in a given theory can be justified by varying levels of theory-related strength, as shown in the table below. In addition, the criminal justice system has defined different levels of evidentiary strength that correspond with the strength of a theory. Based on this framework, there are different possibilities for a misalignment between the strength of a theory and the level of confidence one places in it:

  • An unreasonable skepticism is present when the confidence level is rather low although the theory is rather strong
  • A rather high level of confidence in a rather weak theory indicates the presence of an unreasonably strong belief, like, for example, an unquestioned fundamental assumption about the world or human nature. Note that this doesn’t necessarily have to be undesirable or wrong: the practice of (humanist) religious faith and the maintenance of hope against all odds also corresponds with this kind of misalignment.
  • A rather high level of confidence despite a rather strong evidence base to the contrary represents a delusional or paranoid belief in a falsehood — a claim which is directly contradictory to facts or well established rational/scientific findings.

Part 1/5: The problem with conspiracy theories
Part 2/5: A theory of theories
Part 3/5: What is driving conspiratorial thinking?
Part 4/5: The worldview and the epistemology behind conspiratorial thinking
Part 5/5: What can be done to reduce the prevalence of conspiratorial thinking?



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