curse of knowledge

Once you know something, you cannot easily imagine what it was like not to know it — the knowledge fills in the gaps the novice still sees, and the expert forgets the gaps were ever there.

The curse of knowledge is a cognitive bias first named by Camerer, Loewenstein and Weber (1989): experts lose access to their own pre-expert state, and telling them about the bias does not reduce it. The expert's practiced judgment runs on schemas and compiled productions that the novice has not yet built, so the expert cannot reconstruct what the novice needs to hear — not because the expert has forgotten the facts, but because the expert has forgotten the difficulty. The castle found this bias at the heart of the tacit-knowledge wing: the think-aloud protocol captures the expert's explicit reasoning (the questions asked, the options weighed) but the tacit judgment (the felt sense of the midpoint) is the part the expert cannot narrate, because the curse of knowledge prevents reconstruction of what the judgment felt like before it was practised. The annotated checklist is a bounded bridge — it externalises the explicit layer the curse hides, but the tacit flesh stays with the one who practised.

The bias is structural, not attitudinal: it is not that the expert is unwilling to teach, but that the expert's own cognitive architecture has been rebuilt by practice, and the pre-practice state is genuinely inaccessible. This is why the worked-example effect helps novices (the visible reasoning provides a scaffold the curse removed from the expert's narration) and why the expertise reversal effect reverses it for experts (the scaffold is redundant for those who already have the schemas). The curse is the mechanism behind the tacit-cost gap: the wider the gap between what the expert knows silently and what the expert can say, the deeper the curse has taken hold.