·Psychology & Behavior
Section 1
The Core Idea
In 1990, Elizabeth Newton earned her PhD at Stanford with an experiment so simple it almost seems trivial — and so revealing it reshaped how psychologists think about communication. She divided participants into two groups: tappers and listeners. Tappers were asked to tap out the rhythm of a well-known song — "Happy Birthday," "The Star-Spangled Banner," "Mary Had a Little Lamb" — on a table. Listeners had to identify the song from the tapping alone. Before the listeners guessed, Newton asked the tappers to predict how often the listeners would recognise the song. The tappers predicted 50%. The actual success rate was 2.5%. The tappers were wrong by a factor of twenty. And when the listeners failed, the tappers were visibly frustrated — baffled that anyone could miss something so obvious. The tappers could hear the melody in their heads as they tapped. They literally could not imagine what the tapping sounded like without the melody. That gap — between what the knower experiences and what the audience receives — is the Curse of Knowledge.
The Curse of Knowledge is a cognitive bias in which a person who possesses information finds it nearly impossible to reconstruct the mental state of someone who lacks that information. It is not a failure of empathy, effort, or intelligence — it is a structural limitation of human cognition that affects experts more severely than novices precisely because experts have more knowledge to be cursed by. Once you know something, you cannot un-know it. The knowledge rewires how you perceive the problem, the explanation, and the audience — making it systematically difficult to communicate with, teach, design for, or sell to people who do not share your knowledge. The bias was formally named by economists Colin Camerer, George Loewenstein, and Martin Weber in a 1989 paper, though Newton's tapping study became its most famous illustration. The mechanism is not arrogance or laziness. It is a genuine cognitive limitation: the brain uses its current knowledge state as the default lens for interpreting all situations, including situations where the audience operates from a fundamentally different knowledge state. Imagining ignorance from a position of expertise is one of the hardest things a human brain can do.
The consequences of this bias extend far beyond awkward explanations at dinner parties. In product design, the Curse of Knowledge is the reason engineers build interfaces that make perfect sense to engineers and baffle everyone else. The engineer knows where the settings menu is because she built it. She cannot perceive the screen as a first-time user would — cannot see the cognitive load, the ambiguous labels, the missing affordances — because her knowledge of the system's architecture fills in every gap automatically. In medicine, the Curse of Knowledge explains why doctors routinely overestimate patients' understanding of diagnoses and treatment plans. A physician who says "you have a benign neoplasm" is communicating with perfect clinical accuracy and near-zero patient comprehension. The physician hears a reassuring message. The patient hears "neoplasm" and thinks cancer. The same words, decoded through different knowledge states, produce opposite emotional responses.
For founders, the Curse of Knowledge is arguably the most expensive bias in the startup lifecycle. A founder who has spent three years immersed in a problem space cannot remember what it was like not to understand the problem. Their pitch deck assumes knowledge the investor does not have. Their product onboarding assumes familiarity the user does not possess. Their hiring conversations assume context the candidate has never encountered. Every communication failure — the investor who "didn't get it," the user who churned after day one, the new hire who floundered for months — traces back to the same root cause: the founder communicated from their own knowledge state rather than the audience's. The tragedy is that the founder's depth of knowledge, which should be their greatest asset, becomes the very thing that prevents them from transferring that knowledge to the people who need it most.
What makes the Curse of Knowledge particularly insidious is that it is invisible to the person suffering from it. The tapper does not feel like she is communicating poorly — she feels like the listener is failing to hear something obvious. The expert does not feel like his explanation is impenetrable — he feels like the audience is being dense. The founder does not feel like the pitch is unclear — she feels like the investor is not paying attention. The bias generates a self-serving explanation for every communication failure: the problem is with the audience, not the message. This attribution error prevents the correction that would fix the problem, because the expert never questions whether their knowledge is the obstacle rather than the solution. The most knowledgeable person in the room is often the worst communicator in the room — not despite their expertise, but because of it.
The bias scales with expertise in a way that makes it progressively more damaging the more successful you become. A first-time founder has a modest Curse of Knowledge — they have been thinking about the problem for months, perhaps a year. A serial founder on their fourth company, with deep domain expertise and pattern recognition accumulated across decades, has a severe Curse of Knowledge — every conversation is filtered through layers of context that no audience shares. The paradox is cruel: the founder best equipped to solve the problem is the founder least equipped to explain why the problem matters, because the depth of their understanding has made the problem's importance invisible — as self-evident to them as the melody is to the tapper.
The economic consequences are staggering, though largely invisible in any single instance. Every failed pitch meeting where the investor "didn't get it" represents not just a lost funding opportunity but months of runway consumed pursuing a communication strategy that was never tested on an unknowing audience. Every product feature that requires a help article represents not just a documentation cost but an adoption barrier that compounds across every new user who encounters it. Every strategic directive that the organisation misinterprets represents not just a lost quarter of execution but a compounding misalignment between what leadership intended and what the organisation built. The Curse of Knowledge is not a dramatic, visible failure. It is a slow, invisible tax on every interaction between the knowledgeable and the unknowing — and in a world where founders must sell to investors, products must sell to users, and leaders must sell strategy to organisations, that tax is levied on every consequential communication a company makes.
