How can you tell who is a valid expert, and who is full of B.S.?
On almost any topic of importance you can find a mix of valid experts (who are giving you reliable information) and false but confident-seeming "experts" (who are giving you misinformation). To make matters even more confusing, sometimes the fake experts even have very impressive credentials, and every once in a while, the real, genuine experts are entirely self-taught.
Here are 12 signs we look for in an expert to help us determine whether they are trustworthy.
1. They have deep factual knowledge
Let’s start with the obvious: for most topics, a lot of factual knowledge is required before you can have genuine expertise. This means that a genuine expert will have an impressive command of the relevant (non-debated) facts on the topic of their expertise. Thankfully, it's a lot easier to tell if an expert has a strong command of the non-debated facts than whether they are correct about more controversial claims.
2. They communicate their confidence levels
Not all knowledge is equally well-established. Even theories that are widely accepted enjoy different levels of support from the relevant evidence. When an expert regularly pretends that all their claims are equally well-established, they demonstrate they are willing to make you believe something is certain when it isn't.
It’s a good sign that someone treats their subject with the nuance expected from genuine expertise, when they indicate how confident they are (e.g., “It's been shown in many high-quality studies that…”, or “My best guess is…”), and they explain limitations in the evidence they are using (e.g., “this is unfortunately based on just one study, but that is all that currently exists”)
3. They admit not knowing
Genuine experts also sometimes say that they don’t know the answer to a question, or that the answer is generally not known by anyone. This is important because every topic will have some unknowns, and no expert can know everything about a topic. Telling you when they don't know is a sign that, when they say they do know, they actually do know.
4. They tell you to look at sources other than themselves
This might happen when an expert doesn’t know the answer to a question, or when they want to help you go beyond the answer they can give you. Genuine experts don't seek to be seen as a sole arbiter of knowledge or authority on a topic (which can be an indication that ego, rather than truth-seeking, is a primary motivation for them), but instead encourage you to look at resources other than the ones they have produced.
5. They use logic and evidence
Anyone can use rhetorical devices like emotional appeals, no matter how wrong they are, but a well-reasoned argument that uses valid logic and strong evidence will tend to point toward truth. Or, put another way, using strong logic and strong evidence is easier to do when you're right, whereas emotional appeals are no easier when you're right than when you're wrong.
6. They cite high-quality evidence
Some evidence is much more reliable than other evidence, and those who rely on the less reliable kinds when the more reliable kinds exist probably aren't doing the best job they can at figuring out the truth. For this reason, genuine experts cite high-quality evidence when it exists (e.g., looking at multiple randomized controlled trials for causal claims) rather than low-quality evidence (e.g., just talking about personal anecdotes), and when high-quality evidence doesn’t exist, they cite the highest quality evidence that does exist.
7. They acknowledge the consensus
Consensus views among experts are more often correct than the idiosyncratic views of just one or two experts. The consensus will not always be right, of course, but often it will be the best understanding we have available. That’s why reliable experts are transparent about the degree to which their opinion differs from the majority of experts, provide reasoned explanations for any deviations, and they are cautious not to present fringe theories as mainstream. This shows a deep engagement with the topic of their expertise and also an adherence to ethical standards of honesty and accuracy in communication.
8. They change their mind
Genuine experts will change their minds about topics within their expertise in response to evidence and arguments. It’s hard to become an expert in something without having been wrong from time-to-time.
That means that anyone claiming to be an expert who has never changed their mind probably has not found and corrected their mistakes. Relatedly, changing one's mind in response to evidence is also a sign of the epistemic humility associated with genuine expertise.
Of course, if someone has a long history of being wrong, that is evidence against them being a genuine expert, not in favor of it. But, since everyone makes some mistakes, if they make mistakes from time to time and then note they were wrong and improve their beliefs, that is a sign that they are following the evidence where it leads rather than continuing to believe what they do regardless of the evidence.
9. They Steelman
When you ‘straw man’ an argument, you misrepresent or oversimplify someone else's position to make it easier to attack or refute. Instead of dealing with the actual argument, you replace it with a weaker version that distorts the original point, which you then argue against. The opposite of this is called ‘steelmanning’, and it involves presenting the strongest possible version of an argument you’re objecting to, even if it's more robust than the one originally presented. This approach aims to strengthen the opposing case in order to facilitate a more genuine and constructive debate.
The most reliable experts will accurately present the strongest arguments made by those that disagree with them while pointing out flaws in those arguments, rather than focusing on just weak arguments from the other side or just mocking the other side (including ad hominem attacks rather than focusing on the substance of the claims of the other side). This is important because knocking down a weak argument from the other side of a debate does little to show the other side is wrong; you have to refute the strongest claims of the other side to actually show they are wrong. Additionally, demonstrating a knowledge of the strongest arguments against your own position shows a deeper level of expertise than only understanding the opposing point of view at a superficial level.
10. They clearly explain their reasons for believing
The philosopher Daniel Dennett has said: “if I can’t explain something I’m doing to a group of bright undergraduates, I don’t really understand it myself.” This sentiment is echoed by philosopher John Searle, who said “In general, I feel if you can't say it clearly you don't understand it yourself.”
When communicating with non-experts, genuine experts are often able to give clear, easy-to-follow (and, ideally, checkable) explanations for why they believe what they believe - without dumbing down the points. They avoid unnecessary jargon and technical language (which sounds smart but makes their arguments very difficult for their audience to follow). Not every genuine expert is able to do this, but the ability to do this well is a sign of genuine expertise. This is important because an expert who cannot explain their ideas clearly will end up requiring you to believe them based on their authority rather than engaging with the arguments themselves. And sometimes, people claiming to be experts will hide behind technical expertise and jargon so that you won't notice that their arguments are actually weak.
11. They have a track record
Sometimes genuine experts will have track records of predictions or successes that you can check, and this provides direct evidence of their knowledge or skill. Unfortunately, this only applies to some fields, like chess masters, martial experts who fight in tournaments, experts who make public predictions about the economy or politics, etc.
12. They use multiple lenses
The world is complex and multi-faceted, and any one simple theory is going to fail to explain a lot of what's really going on. For this reason, genuine experts tend to look at problems from multiple frames and perspectives; they don't act as though one way of looking at things solves all problems, or that one solution works for all problems, or that one simple theory explains everything.
So the next time you hear claims from an alleged expert on a topic that is important to you, you may want to consider: how many of these signs of expertise do they exhibit? You can use this checklist, considering if they:
have deep factual knowledge
communicate their confidence levels
admit not knowing
tell you to look at sources other than themselves
use logic and evidence
cite high-quality evidence
acknowledge the consensus
change their mind
steelman
clearly explain their reasons for believing
have a track record
use multiple lenses
And if you’re seeking to be an expert in something yourself, you may want to ask yourself: “to what extent do I exhibit these traits?”Being able to discern genuine expertise from B.S. requires good judgment. If you’d like to improve your skills at making accurate judgments, why not try our Calibrate Your Judgment tool, created in partnership with Open Philanthropy: