The Curse of Knowledge: Why Experts Explain Badly

An electrician finishes inspecting a house and explains the problem to the owner. “Your DB board’s fine, but you’ve got no earth leakage on the geyser circuit and the RCD’s tripping because of a neutral fault on the plugs in the kitchen.” He says it kindly, clearly and in what, to him, is plain English.

The homeowner nods, says “Right, OK,” and understands almost nothing. She doesn’t know whether this is urgent, expensive or dangerous. She doesn’t want to look silly by asking. She calls a second electrician for a “second opinion”, which mostly means a second explanation.

The first electrician didn’t do anything wrong, exactly. He knows his trade thoroughly. That’s the problem. Once you know something well, it becomes almost impossible to remember what it was like not to know it, and to see your words the way a newcomer does.

Psychologists call this the curse of knowledge. It affects accountants, lawyers, software developers, mechanics, designers and anyone else who has become good at something. And because it’s invisible to the person suffering from it, it quietly costs businesses customers every day.

One Like insight: The better you know your subject, the harder it is to explain it to someone who doesn’t.

The tapping experiment

In 1990, a Stanford psychology student named Elizabeth Newton ran a simple experiment that has since become the classic illustration of this problem. She divided people into two groups: “tappers” and “listeners”. Each tapper picked a well-known song, such as “Happy Birthday”, and tapped out its rhythm on a table. The listener had to guess the song.

Before the listeners guessed, Newton asked the tappers to predict how often they’d succeed. They estimated that listeners would get it right about half the time. In reality, across 120 songs, listeners identified just three, a success rate of 2.5%. The tappers thought they were getting their message across one time in two. They were managing one time in forty.

Chip and Dan Heath, who popularised the experiment in their book Made to Stick and a 2006 Harvard Business Review article, explain why. When a tapper taps, they can’t help hearing the tune in their head. The listener hears only what the Heaths call “a kind of bizarre Morse code”. The tappers were astonished at how hard the listeners found it, because to them the song was obvious.

That’s the curse of knowledge in its purest form. Once you know something, it’s extraordinarily difficult to imagine not knowing it. And because you can’t switch off what you know, you can’t easily hear your own message the way someone else hears it.

Highlight: You hear the whole song. Your customer hears only the taps.

Why experts can’t un-know

The Heaths point out that business is full of tappers and listeners: managers and employees, head office and the front line, marketers and customers. In each case, one side has years of background knowledge and the other doesn’t. The side with the knowledge speaks in summaries, shorthand and abstractions that feel perfectly clear because they’re standing in for a mass of detail in the speaker’s head. The other side hears only the summary.

In small businesses, the curse tends to show up in a few predictable places:

• Jargon and acronyms. Terms you use every day, like “VAT-inclusive”, “turnaround time” or “DB board”, can be meaningless or intimidating to a customer.
• Skipped steps. You explain the process from step three because steps one and two are so obvious to you that you’ve forgotten they’re steps.
• Vague promises. Phrases like “end-to-end solutions” or “a holistic approach” summarise something real in your head and mean almost nothing to anyone else.
• Missing context. You tell a customer the job will take “a couple of days” without explaining that it depends on parts arriving, so when it takes a week they feel misled.

The cruel part is that customers rarely tell you they’re confused. Like the homeowner nodding at the electrician, they say “OK”, fill in the gaps with guesses and quietly decide whether to trust you.

Highlight: Customers rarely say “I don’t understand.” They say “OK” and go elsewhere.

Breaking the curse

You can’t un-know what you know, so the solution isn’t to try harder to imagine ignorance. It’s to change how you communicate and to check your work against people who don’t share your knowledge.

The Heaths’ main remedy is concrete language. Abstract statements feel clear to the person who knows the detail behind them, but concrete ones are clear to everyone. Their example is the American grocery chain Trader Joe’s. Its formal mission statement could belong to almost any retailer. But it also described its target customer, half-jokingly, as an out-of-work college professor driving a very old Volvo. Nobody believes that customer literally exists, but the picture gives every employee a shared, specific sense of who they’re serving.

Stories work in the same way, because it’s almost impossible to tell a story without being specific. “We pride ourselves on reliability” is a tap. “Last winter, when the delivery van broke down, our driver borrowed his brother’s bakkie to get the last three orders out before closing” is the whole song.

The other remedy is testing. The tappers would have learned the truth instantly if they’d tapped for a few people before predicting. In business, that means showing your explanation, quote, email or web page to someone outside your field, a friend, a new employee or a customer, and asking them to explain it back in their own words. Where they stumble is where your knowledge has filled a gap that your words left empty.

Highlight: Abstract words feel clear to the person who knows the details. Concrete words are clear to everyone.

What this means for a small business

The curse of knowledge grows with experience, which means the most expert people in your business are often the least able to see the problem. That’s not a criticism; it’s simply how knowledge works. The fix is to build checks into the way you communicate.

Start a “jargon list” of terms your team uses that customers might not understand, and agree on plain alternatives. When you explain a job, a price or a process, say what it means for the customer: what happens next, when, how much, and what could change. Replace abstract claims with a specific example or a short story. And before anything important goes out, a new price list, a proposal template, an explanation of your services, ask someone outside your field to read it and tell you what they think it says.

A few questions can help:

• Which words do we use every day that a customer might not know?
• When customers ask questions, what do they most often misunderstand?
• Where do we say something abstract that we could replace with an example?
• Who could we ask, this week, to explain our offer back to us?

Which brings us back to the electrician and the confused homeowner. He could have said: “Your main board is fine. There’s a fault in the kitchen plug circuit that keeps tripping your safety switch. It’s not dangerous right now, but it should be fixed this week. It’s about two hours’ work.” Same knowledge, same expertise. The difference is that this time, the customer hears the song.

Sources

1. Chip Heath and Dan Heath, “The Curse of Knowledge”, Harvard Business Review, December 2006. Source of the Elizabeth Newton experiment details, the Trader Joe’s example and the quoted phrase.
2. Chip Heath and Dan Heath, Made to Stick: Why Some Ideas Survive and Others Die (Random House, 2007).
3. Elizabeth Newton, doctoral dissertation, Stanford University, 1990 (as reported by the Heaths).