Once you know how to do something, it’s hard to remember what it was like not to know it. Researchers call this the curse of knowledge. In a 1990 Stanford study, people tapping out well-known songs expected listeners to name about half of them, and listeners named 2.5%. When your instructions feel clear and the work still comes back wrong, this is usually why.
You showed your new hire how to send the end-of-month invoices. You pulled it up on your screen, walked through it once, and said, “Pull the hours, double-check the rates, and send it from the billing inbox.” She nodded and took notes. Two days later a client emails asking why they were billed the old rate. When you ask her about it, she says, “I didn’t know the rates had changed. Where would I have seen that?”
To you, it was obvious. You raised those rates in September, you know which clients moved to the new pricing, and in your head “double-check the rates” meant “check them against the new pricing sheet in the shared folder.” You just never said that part out loud, because you didn’t need to hear it.
The song only plays in your head
In 1990, Elizabeth Newton, a PhD student in psychology at Stanford, set up a simple game. One person, the tapper, picked a well-known song like “Happy Birthday” and tapped out the rhythm on a table. The other person, the listener, tried to name the song.
Before each round, Newton asked the tappers to guess how often the listener would get it right. They guessed about half the time.
Across 120 songs, the listeners named 3. That’s 2.5%.
The tappers were surprised, and some of them were frustrated with the listeners. While they tapped, they could hear the whole song playing in their heads, the melody and the words and all of it. The listener just heard someone knocking on a table. The tappers couldn’t turn off what they knew long enough to hear what the listener was actually hearing.
A year earlier, economists Colin Camerer, George Loewenstein, and Martin Weber had given this a name, the curse of knowledge. Once you know something, it’s very hard to set that knowledge aside and picture what someone without it would understand.
(Fair warning: Newton’s study was her dissertation and was never published in a journal. It got famous because Chip and Dan Heath wrote about it in their book Made to Stick. The bigger idea has plenty of research behind it, but the 2.5% number comes from that one study.)
Why owners get hit the hardest
The longer you’ve done something, the worse this gets. You’ve sent those invoices a hundred times. Steps you used to have to think about are automatic now, so they don’t show up when you explain the task. You aren’t leaving them out on purpose, you honestly don’t notice they’re there.
That’s how “I’ve told her twice” and “I don’t know what she wants from me” can both be true at the same time. You did explain it. She just heard the knocking.
I wrote about the other half of this in How to delegate without taking it back, which is about handing off a clear outcome. The curse of knowledge is about everything between the handoff and that outcome, the steps that feel too obvious to mention.
What this looks like in real life
Picture an owner of a small cleaning company, we’ll call her Dana. She’s run the business for eight years, and this fall she hired her first office manager. Every Friday the office manager is supposed to confirm the next week’s schedule with clients, and every Monday something is off. One client wasn’t expecting a crew. Another one was told the wrong time.
Dana’s instructions were one sentence: “Just confirm everybody for next week.” For Dana, that sentence carries eight years of knowing which clients want a text and which want a phone call, which ones always move their day around, and that holiday weeks need a second check. For her new office manager, it’s a list of names and numbers.
If Dana were one of my clients, I wouldn’t have her explain it again, because her explanation is the problem. I’d have her do the confirmations herself one Friday, out loud, while her office manager writes down every single step, including the ones Dana would never think to mention. Then the next Friday the office manager does it while Dana watches and stays quiet until it’s done. Most owners are surprised by how long that list gets, and that list is the set of instructions they thought they’d already given.
Watch for it this holiday season
The next two months bring seasonal help, more handoffs while people are out, and owners moving too fast to slow down and explain things. That’s a lot of tapping. If you’re handing something off before the holidays, plan on there being steps you won’t think to say.
Your homework
Pick one task you’ve handed off that keeps coming back a little bit wrong. The next time it comes up, ask the person doing it to walk you through how they’re going to do it, in their own words, before they start. Don’t correct them as they go. Just write down every spot where what they say doesn’t match what’s in your head.
Those spots are the parts of the song they couldn’t hear. Fill them in, and write them down somewhere they can find them next time.
If you want someone to help you figure out what’s in your head that never made it to your team, that’s what I do.
Frequently asked questions
What is the curse of knowledge? It’s the difficulty of imagining what it’s like not to know something once you know it, which makes experts overestimate how clear their explanations are. The term comes from a 1989 economics study by Colin Camerer, George Loewenstein, and Martin Weber.
What was the tapping study? In Elizabeth Newton’s 1990 study at Stanford, people tapped out well-known songs and predicted listeners would name about half of them. Listeners named 3 out of 120, or 2.5%.
How do I give clearer instructions to employees? Have them explain the task back in their own words before they start, walk through it out loud while they take notes, and write down the steps you’d normally skip because they feel obvious to you.
Sources: Newton, E. L. (1990). The rocky road from actions to intentions (Doctoral dissertation). Stanford University. · Camerer, C., Loewenstein, G., & Weber, M. (1989). The curse of knowledge in economic settings: An experimental analysis. Journal of Political Economy, 97(5), 1232–1254.
