While assessing the credibility of sources is always important, the next pandemic will make this a matter of life and death. Those of us who are not epidemiologists or medical professionals must rely on others for information. While some people will provide accurate information, there will also be well-meaning people unintentionally spreading unsupported or even untrue claims. There will also be people knowingly spreading disinformation. Your well-being and even survival will depend on being able to determine which sources are credible and which are best avoided.
There are two types of credibility: rational and rhetorical. While a bit oversimplified, rational credibility means that you should logically believe the source and rhetorical credibility means that you feel you should believe the source. The difference between the two rests on the distinction between logical force and psychological force.
Logical force is objective and is a measure of how well the evidence for a claim supports it. In the case of logical arguments, this is assessed in ways ranging from applying the standards of an inductive argument, to creating a truth table to working through deductive proof. To the degree that a source has rational credibility it is logical to accept the relevant claims from that source.
Psychological force is subjective and is a measure of how much emotional influence something has on a person’s willingness to believe a claim. This is assessed in practical terms: how effective was it in persuading someone to accept the claim? While the logical force of an argument is independent of the audience, psychological force is audience dependent. What might persuade one person to accept a claim might enrage another into rejecting it with extreme prejudice. Political devotion provides an excellent example of the relativity of psychological force. If you present a claim to Democrats and Republicans and attribute it to Trump, you will get different reactions.
Psychological force provides no reason or evidence for a claim. But it is more effective at persuading people than logical force. To use an analogy, the difference between the two is like the difference between junk food and kale. While junk food is tasty, it lacks nutritional value. While kale is good for you, many people find it unappealing. Because of this distinction, when people ask me how to “win” arguments, I always ask them what they mean by “win.” If they mean “provide proof that my claim is true”, then I say they should use logic. If they mean “get people to feel I am right, whether I am right or not”, then I say they should focus on psychological force. Rhetoric and fallacies (bad logic) have far more psychological force than good logic, which creates no end of problems.
The vulnerability of people to psychological force makes it dangerous during a pandemic. When people assess sources based on how they feel, they are far more likely to accept disinformation and misinformation. This leads to acting on false beliefs which can get people killed. Health and survival during a pandemic depend on being able to correctly assess sources and this requires being able to neutralize (or at least reduce) the influence of psychological force. This is a hard thing to do, especially since the fear and desperate hope created by a pandemic makes people even more vulnerable to psychological force and less trusting of logic. It is my hope that this guide will provide some small assistance to people in the next pandemic.
One step in weakening psychological force is being aware of factors that are logically irrelevant but psychologically powerful. One set of factors consists of qualities that make people appealing but have no logical relevance to whether their claims are credible. One irrelevant factor is the appearance of confidence. A person who makes eye contact, has a firm handshake, is not sweating, and does not laugh nervously seems credible, which is why scammers and liars learn to behave this way. But reflection shows these are irrelevant to rational credibility. To use my usual silly math example, imagine someone saying “I used to think 2+2=4, but Billy looked me right in the eye and confidently said 2+2=12. So that must be true.” Obviously, there are practical reasons to look confident when making claims, but confidence proves nothing. And lack of confidence disproves nothing. To use a silly example, “I used to think 2+2=4, but Billy seemed nervous and unsure when he said that 2+2=4. So, he must be wrong.”
Rhetorical credibility also arises from qualities that you might look for in a date or friend. These can include physical qualities such as height, weight, attractiveness and style of dress. These also include age, ethnicity, and gender. But these are all logically irrelevant to rational credibility. To use the silly math example, “Billy is tall, handsome, straight, wearing a suit, and white so when he says that 2+2=12, he must be right!” Anyone should recognize that as bad “logic.” Yet when a source is appealing, people tend to believe them despite the irrelevance of the appeal. One defense is to ask yourself if you would still believe the claim if it was made by someone unappealing to you.
Rhetorical credibility also arises from good qualities that are irrelevant to rational credibility. These include kindness, niceness, friendliness, sincerity, compassion, generosity and other virtues. While someone who is kind and compassionate will usually not lie, this does not entail that they are a credible source. To use a silly example, “Billy is so nice and kind and he says 2+2=12. I had my doubts at first, but how could someone so nice be wrong?” To use a less silly example, a kind person might be misinformed and unwittingly pass on dangerous disinformation with the best of intentions. A defense is to ask yourself if you would still believe the claim if it was made by someone who has bad qualities. But what about honesty? Surely, we should believe what an honest source says.
While it is tempting to see honesty as the same thing as telling the truth, a more accurate definition is that an honest person says what they think is true. They could be honestly making a false claim. A dishonest person will try to pass off as true what they think is untrue. And even dishonest people do not lie all the time. As such, while honesty does have a positive impact on rational credibility and dishonesty has a negative impact, they are not decisive. But an honest source is preferable to a dishonest one. Sorting out honest and dishonest sources can be challenging.
Group affiliation, ideology and other values have a huge impact on how people judge rhetorical credibility. If a claim is made by someone on your side or matches your values, you will probably be inclined to believe it. For example, Trump supporters will tend to believe what Trump says because Trump says it. If a claim is made by the “other side” or goes against your values, then you will tend to reject it. For example, anti-Trump folks will usually doubt what Trump says. An excellent historical example of how ideology can provide rhetorical credibility is the case of Stalin and Lysenko—by appealing to ideology Lysenko made his false views the foundation of Soviet science. This provides a cautionary tale worth considering. While affiliations and values lead people to engage in motivated “reasoning” it is possible to resist their lure and try to assess the rational credibility of a source.
One defense is to use my stupid math example as a guide: “Trump says that 2+2=12; Trump is my guy so he must be right!” Or “Trump says 2+2=4, but I hate him so he must be wrong.” Another defense is to try to imagine the claim being made by the other side or someone who has different values. For example, a Trump supporter could have imagined Obama or Clinton making the claims about Hydroxychloroquine that Trump made. As a reverse example, Trump haters could try the same thing. This is not perfect defense but might help.
While this short guide tries to help people avoid falling victim to rhetorical credibility standards are also needed to determine when you should probably trust a source—that is, standards for rational credibility. That is the subject of the next essay.