Published on April 23, 2025 3:35 AM GMT
What would it take to convince you to come and see a fish that recognizes faces?
Note: I'm not a marine biologist, nor have I kept fish since I was four. I have no idea what fish can really do. For the purposes of this post, let's suppose that fish recognizing faces is not theoretically impossible, but beyond any reasonable expectation.
Imagine someone comes to you with this story:
"I have an amazing fish. Marcy. She's an archerfish—you know, the kind that can spit at insects? Well, I trained her to spit at politicians.
"It started as a simple game. I’d tap a spot, she’d spit at it, and get a treat. One day I put a TV beside the tank and tapped when a politician came on. Eventually, she started hitting the politicians before I tapped. She ignored talk show hosts, but hit every politician she's seen before.
"Now she seems to recognize them on her own. I mark targets in advance, and she hits them. Every time.
"So, want to come see? I want to know if she’ll do it for someone else before I call a scientist. Promise it'll be a hoot."
Would you go?
Perhaps more importantly: Why?
Here's some possible answers:
- "It sounds fun and weird, and I like fun and weird. Even if it’s a prank, it’s probably a good story.""I'm curious. I want to spot the trick—there has to be one, right?""I don’t have a better plan today. Might as well.""I like the guy and I want to support his enthusiasm, even if I think he’s wrong.""If it is real, that’s fascinating—and I don’t want to miss it.""Sounds like the setup to a dumb YouTube stunt. Waste of time.""If a fish could recognize faces, I’d have heard about it from a more reputable source.""I'm too tired of this nonsense. I’m burned out with all these wild claims.""Even if it’s true, it doesn’t matter to me."
Which of these responses are truly rational?
All of them. Or none.
Each of these responses could be logically based on valid prior beliefs. But each response could also be a knee-jerk heuristic. A fast answer masquerading as thought. It depends on whether you actually ran the mental math, or just slapped a label on the situation and moved on.
How often do we pat ourselves on the back for being rational when we’re really just fluent in sounding rational?
This isn’t really about fancy, fantasy fish.
It’s about hearing someone rave about a new mental health app and wondering if it’s worth the download. It’s about dismissing a friend’s obsession with lucid dreaming or a new language-learning technique. It’s about ignoring the quiet recommendation of a colleague to try a niche productivity method. It’s about skipping the article on that weird physics result because it sounds too much like clickbait. It’s about side-eyeing the neighbor’s homemade contraption until it shows up in a patent filing. It’s about reflexively assuming a celebrity’s foundation is just for PR—until it isn’t. It’s about your kid saying they built a working hovercraft and your first instinct being to laugh.
It’s about the little bets we pass up every day because our expectations got there first. Sometimes, we dismiss things too quickly. Or accept them too quickly when skepticism is warranted. Or go through the motions without genuine curiosity either way.
So here’s the question:
What would it actually take for you to give something improbable a fair shot?
Not just a yes or no—but a real evaluation. When do you update your priors? When do you investigate? And when do you just laugh and say, “Sure, let’s see the fish.”
Note: So I lied. I had no idea what fish can really do when I started this post. Since then I have learned that fish can do a lot more than I thought. This includes recognizing faces, doing simple math, and following commands. I decided not to change my example, so you all can have the same surprise that I did. I did, however, change the story to include the kind of fish that has actually been shown (in a lab) to recognize human faces.
Discuss
