What is Dysrationalia, and why trust can make you irrational

Why do smart people fall for stupid things? 

This week, we’re going to discuss an important part of the answer to that question: trust. And, in doing so, we’ll also discuss how to trust people more rationally and introduce you to the concept of dysrationalia.

Trust Can Make Us Irrational

It's easy to look around at the stupid-seeming things that other people believe (e.g., people who join harmful cults, get scammed by a con artist, become vocal evangelists for a placebo treatment, or jump on the hype train of some outrageous new bubble) and wonder: "How on earth can they be so foolish?"

The answer, a lot of times, is simply the trust they have in someone else.

In other words, maybe if you were to evaluate an idea yourself, you would see it as foolish, false, or dangerous. But, instead, if someone you trust tells you that the idea is the next big thing, or that it will change your life, make you rich, or solve a problem that you desperately want solved, then you find yourself in a predicament. You can either believe:

1. That this impressive person whom you deeply trust is deceiving you (whether accidentally or not), or

2. That this impressive person whom you trust is right - and your life will be way better because of it!

If your trust in the person is great enough (or, at least greater than your level of skepticism), you might end up picking option 2 instead of option 1. But option 2 may also win you over for one or more of these other reasons:

• You so desperately want this to be real - you want to be special, or rich, or to have your biggest problems finally solved

• It's difficult and painful to believe that the person you trust so much is deceiving you or so wrong about something important

• You sense it will damage the relationship you have with that person, if you refuse to believe (and you care deeply about the relationship)

• You have a hard time saying 'no' - perhaps it makes you very anxious to do so

What's more, there are a lot of factors that can impact how much we trust someone that don't always correlate with them actually being trustworthy, such as:

• Credentials - when relevant to the topic of discussion, credential can be helpful indicators, but just because someone has a PhD in one field doesn't mean you can trust them in other areas

• How someone looks - if someone is immaculately dressed, imposingly tall, or unusually attractive, it can shape our view of what they tell us

• Charisma - some people have a personality that makes us want to believe them, but this doesn't mean that what they are saying is accurate

• Liking - the more we like someone, the more amenable we may be to what they tell us

• Authority - if someone appears to be an authority on a topic, or they seem to get respect from others we respect, we may assume that they must be giving us accurate information, even though this isn't always the case

• Persuasiveness - some people are simply good persuaders - and so we may believe them merely because of this ability, rather than because what they are saying is true

• Ties - if someone is a family member, or part of our community, or a friend of a close friend, or simply similar to us, we may be more prone to believe what they tell us

What's tricky is that some people, even those who appear trustworthy, don't have your interests at heart. They may be trying to take advantage of you by gaining your trust. What's sometimes even trickier though, is that a person who appears trustworthy may themselves be misled - either by someone else tricking them, or through their own errors in reasoning that have led them to a false conclusion. They may genuinely believe what they are trying to convince you of, and yet be completely mistaken.

Although the effect of believing something due to trust often happens when just one person we trust causes us to believe in something, the effect is magnified when more people around us believe. Being recruited into a harmful cult by a trusted friend can be difficult, but leaving a cult - at which point all of our close friends are believers - is far more difficult. And growing up in an authoritarian regime, where everyone we've met seems to believe a certain thing, makes it that much more difficult to resist believing it too.

There are a great many foolish things that even smart people end up believing, simply because people believe people. 

To be clear, this is not the only mechanism by which smart people fall for foolish things, but it does appear to be a common-but-rarely-examined source of irrational thinking. More broadly, there's a deeper concept at play that explains why smart individuals still fall into irrational thinking: dysrationalia.

What is Dysrationalia?

There is a difference between intelligence and rationality. We have a whole other article on what rationality is, but, in short, a popular theory of rationality tells us that it comes in two flavors:

Epistemic rationality: this is all about how your belief-forming mechanisms (e.g., how you look for evidence, what evidence you trust, etc) lead you to beliefs that match reality. If you regularly trust low-quality evidence and form false beliefs as a result, then you are low in epistemic rationality. If, on the other hand, you adjust your degree of belief to the strength of evidence you get, and you actively seek out high quality evidence on topics that are important to you, then you have strong epistemic rationality.

Instrumental rationality: this is all about how your actions lead you towards your goals. If you regularly act in ways that take you away from your goals, then you are low in instrumental rationality. If, on the other hand, the actions you choose to take reliably take you towards your goals, and your goals are based on your values, or based on what's most fundamentally important to you, then you have strong instrumental rationality.

This way of thinking about rationality is not without objections, but it is widely used and very useful. 

Notice that neither epistemic nor instrumental rationality is the same concept as the concept of intelligence. There are lots of debates over how exactly we should understand intelligence but, however you do so, there will be some difference between it and rationality.

There is evidence that rationality and intelligence are correlated. But they can come apart; it is possible to have a lot of one without much of the other. Smart people can still hold beliefs and make choices that are illogical or misguided. In fact, essentially all smart people will do so some of the time. But some will do it more than others.

In short, dysrationalia is the tendency of people to engage in  irrational thinking or behavior, even when they have sufficient intelligence to avoid doing so. 

Originally, dysrationalia was proposed as a kind of learning difference, similar to how conditions like dyslexia and dyscalculia were viewed (hence the words ‘dysrationalia’, ‘dyslexia’, and ‘dyscalculia’ sharing roots and structure). At the time, diagnostic guidelines for diagnosing learning differences like dyslexia or dyscalculia (outlined in the Diagnostic and Statistical Manual of Mental Disorders, commonly called ‘The DSM’) required a discrepancy between IQ and achievement. This meant that someone needed to show a significant gap between their intellectual potential (measured by IQ) and their actual performance in reading or math to receive a diagnosis. This was the case until 2013.

However, the approach to learning differences has evolved. The DSM has now removed the IQ-achievement discrepancy requirement for diagnosing learning differences. The concept of dysrationalia, too, has evolved. It is now seen less as a learning difference and more as a way to understand the limitations of human reasoning that even affect those with the highest levels of intelligence. As such, contemporary discourse on dysrationalia focuses on the causes of irrational beliefs and behavior that can affect us, regardless of our intelligence - things like:

• Biases

• Heuristics

• Emotional influences

• Social pressures

• Motivated reasoning

• The role of identity

• The impacts of stress or fatigue

And more.

So, as we’ve seen, trust is a mechanism by which smart people can end up with quite irrational beliefs. Does this mean it’s bad? Of course not! Reflecting on why we trust people and how we can do so more rationally can help us to get the benefits of trusting people while mitigating the deleterious effects it can have on our rationality.

Why do we trust people?

There are good reasons and bad reasons that we trust people. Let’s start with a good reason. Studies consistently find that having close adult friendships is associated with increased well being. Philosopher Judith Baker outlines a kind of trust that she calls ‘friendship trust’ that illustrates how having close adult friendships involves trusting (even trusting that can involve seemingly-irrational behavior). She imagines that a friend of hers has been accused of a crime and writes:

“What others regard as evidence against her isn’t considered by me as evidence at all. It is not that I close my ears to what people say, or refuse to look at, or repress, the facts. I believe that there is an explanation for the alleged evidence, for the accusation, which will clear it all up.

In advance of hearing the case, I am prepared to believe that there is such an explanation. I am biased in favour of my friend … I am committed to her being innocent. Moreover, as the case grows, as evidence mounts, I do not have corresponding mounting doubts. Although there may be a time when I cease to believe in my friend, there are no limits which can be set in advance, on epistemic grounds, which would determine the point at which it is irrational to continue to trust her.”

For Baker, this kind of trust is part of a deep friendship. Of course, this kind of trust can be placed irrationally (for example, when you are aware of overwhelming evidence of your friend’s untrustworthiness) but, given the value of close interpersonal relationships in our lives, many of us will find it instrumentally rational to commit to some amount of this kind of trust.

But there are plenty of bad reasons we trust others. These are reasons that aren’t connected to our goals and/or truth, and are instead often based on harmful biases. For example, a recent meta-analysis of 338 studies of trust found that people factor in things like race and (as we mentioned earlier) attractiveness into judgements of trustworthiness - even though those things have nothing to do with reliability, ability to discern the truth, or anything else that might warrant trust. The authors of that meta-analysis represent their findings as follows:

Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10083508/

Terms with a (+) represent correlational findings, italicized terms represent significant correlational findings. Terms with a (*) represent experimental findings, bolded items represent significant experimental findings.

So, although friendship trust, as Baker describes it, may play a crucial role in fostering close relationships and enhancing our well-being, it's important to reflect critically on why, when, and where we place our trust.

How to think more rationally about trusting people

When rationality is discussed, it's often talked about at the level of the individual. But quite a bit of our thinking we necessarily outsource to others. After all, we can't make sense of everything ourselves. When we allow someone into our circle of epistemic trust who doesn't deserve to be there, that can jeopardize our rationality. Hence, an important meta-skill of rationality is knowing who to trust - and not being suckered into trusting those who don't deserve it.

Here’s a simple tip to help hone that skill.

Other than trying to reflect on why you trust someone, one thing that may be helpful is to draw on a distinction made by philosophers who specialize in trust: the distinction between two-place and three-place trust. Imagine you’re talking about a friend named Erin:

Two-Place Trust: You might simply say "I trust Erin." This means you generally believe Erin is a trustworthy person, but you haven’t specified what you trust her to do. This is a broad, generalized form of trust. It’s called two-place because it can be expressed as a schematic (“Person A trusts person B”) that has two variables in it.

Three-Place Trust: Or you might say "I trust Erin to feed my cat while I'm away." Here, you’re clearly stating that your trust in Erin applies specifically to the task of feeding your cat, not necessarily to other aspects of her behavior. This is a specific form of trust that is context-dependent. It is called three-place because it can be expressed as a schematic (“Person A trusts person B to X”) that has three variables in it.

You can trust a person in one way or in one domain but not another. Or, put another way, earning trust is multi-dimensional. It requires demonstration of trustworthiness in several different ways, such as:

• You know they wouldn't betray you and that they care a lot about you

• You know that they vet evidence carefully, come to their beliefs in a rigorous way, and approach new information skeptically

• You know that they are extremely knowledgeable about a specific topic area

Being strong in one of these domains doesn't automatically make someone strong in another. So, viewing someone as trustworthy in one of these domains shouldn't cause you to view them as trustworthy in the other ones. And yet, because many people implicitly treat trust as two-place, that's what they do.

If you treat all trust as two-place trust, it can put you at a lot of risk because someone you trust may have a very bad idea that they really want you to believe in. It may be hard to reject that idea because you trust them so much -  and that may mean joining a harmful cult, buying into the peak of the next bubble, risking your health on an ineffective treatment, or being scammed.

This doesn’t have to mean you give up or forgo the deep kind of trust that Baker calls ‘friendship trust’; you can have that kind of loyalty and commitment to another person, trusting in their goodness or their value, while still not giving them two-place trust. For instance, you can have deep friendships with people who you don’t necessarily trust to: 

• Be on time for everything

• Treat something fragile with care

• Not tell you the headline of an article as if it’s true, without reading the full article and reflecting on or checking relevant facts

And so on.

The key takeaway is to move from blind, generalized trust to more nuanced, context-specific trust. By using three-place trust, you can preserve your relationships and respect for someone's character while maintaining a rational approach to contexts that require more critical reflection - where their abilities, knowledge, or judgment might not be as strong. We all have weaknesses - and this includes the people we feel trust towards - having deep personal connections does not require pretending that’s not true.

If you want to take your thinking about trust even further, why not try our Effective Trust Repair tool, that will teach you skills for repairing your relationships, by constructing or requesting effective apologies.

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