The simplest way I know to evaluate whether to believe someone is to look at what happens to them after they say it.
What happens when you think they’re right, and what happens when you think they’re wrong?
For example, what if they benefit when you believe them, but nothing happens when you don’t?
| When you believe them | When you don’t believe them | Should you trust them? |
|---|---|---|
| 🔺 | ➖ | ❌ |
The idea being that, if they have no downside for being thought wrong, why should they avoid giving you bad advice? As long as they can occasionally get you to do something that they want you to do, they’ll come out net positive.
I find that evaluating the truth of other people’s statements this way works in a lot of situations, including but not limited to: deciding whether to take someone’s advice or not; whether you can trust that someone really believes in something that they espouse; reading blog posts;1 figuring out whether something is just “cheap talk”/PR; spotting genuinely good people (in the moral sense).
So what does it look like in every case?
| When you believe them/When they’re right | When you don’t believe them/When they’re wrong | Should you trust them? | |
|---|---|---|---|
| 🔺 | 🔺 | ❌ | Paid speakers, life coaches |
| 🔺 | ➖ | ❌ | Unsolicited advice, academics, politicians (to some extent), financial traders without their own money at stake |
| 🔺 | 🔻 | ⭕ | Hedge fund managers, “honest” professions2 |
| ➖ | 🔺 | ❌ | Double agents, saboteurs |
| ➖ | ➖ | ⭕ | Disinterested third parties, mediators |
| ➖ | 🔻 | ⭕ | Concerned friends, unpopular opinions |
| 🔻 | 🔺 | ❌ | Double agents, saboteurs |
| 🔻 | ➖ | ⭕ | “Soul in the game,” idealists, reformers |
| 🔻 | 🔻 | ⭕ | Martyrs, tragic heroes |
This is not an end-all-be-all; it’s certainly possible that someone with skin in the game might be mistaken or give untrustworthy advice, or that someone with a conflict of interest might say something truthful. Ideally, you’d evaluate everything you hear based on its truth, not based on its speaker, but in the end no one has time to critically evaluate everything they come across. These should be taken more as baseline levels of confidence: knowing nothing about this person except what that have to gain and lose, how much credibility should I afford them? How much attention should I bother to spend examining or refuting what they have to say?
↥1 Including this one! Take this framework with a grain of salt and evaluate critically whether you think it’s true.
↥2 This case gets misunderstood a lot as a conflict of interest, where people only see the fact that they gain from being right; it’s not a conflict of interest because e.g. hedge fund managers still have an incentive to not be wrong.
Intentionally Irrational