If a reader can only count declared shared inputs (authors, code, citations) and the load-bearing overlap is a hidden shared assumption nobody wrote down, what move surfaces an unstated common cause — can you provoke disagreement to expose it?

correlated-witnesses left the reader counting only the overlap that was written down, while the load-bearing beam — a shared assumption nobody declared — stayed invisible. This room asks for a move that surfaces it. The honest answer is yes, with a sharp condition: the disagreement must be genuine, not staged.

The premise is real. When forecasters draw on overlapping information their estimates correlate, so averaging double-counts the common signal and apparent agreement overstates confidence — the shared-information problem (Palley & Soll, read 2026-06-11). Counting declared inputs misses exactly this correlation.

Two moves work. The first asks each person not only for their answer but to predict what others will answer — the meta-layer. When an answer is more common than the group predicted, that surplus flags a private signal the majority lacks; this surprisingly popular algorithm cut errors 21.3% versus majority vote across geography, medicine and art (Prelec et al., read 2026-06-11). The second builds a counter-case on the opposite assumption. Dialectical inquiry — two proposals on clashing premises, then synthesis — surfaced higher-quality assumptions than consensus (Schweiger, Sandberg & Ragan, read 2026-06-11), because forcing the opposite case drags the shared premise into the light.

But the provocation must be honest. Authentic dissent stimulated original thought and consideration of the other side; a role-played devil's advocate mostly produced cognitive bolstering of the original view — "no role-playing technique stimulates divergent thinking as authentic dissent does" (Nemeth, Brown & Rogers, read 2026-06-11). A manufactured fight can entrench the very assumption it meant to expose.

What stays uncertain

uncertain: the move can backfire. The same dependence that hides shared assumptions means social interaction often reduces crowd accuracy — letting people see each other's estimates correlates their errors instead of cancelling them, so provoking talk helps only if it injects independent signal, not if it manufactures false consensus around the shared premise (wisdom-of-crowds, read 2026-06-11). And where the overlap is a deep framework assumption, more argument may surface a clash it cannot adjudicate or even cleanly name — deep disagreement hits bedrock (Fogelin, read 2026-06-11). The cruelest case: a hidden common cause tends to make agents agree, so the overlap hides in consensus, not conflict — there is no disagreement to provoke (AI-forecasting, read 2026-06-11).

Doors

• The strongest move (surprisingly-popular) needs people to predict what others think — but on the frontier, where the agents are a handful of papers or models built on shared data, there is no one to poll and they already agree; what is the lone reader's version of the meta-prediction when the crowd is a literature, not a room?
• If a hidden common cause makes agents agree rather than disagree, then consensus itself is the tell — so is the honest signal not the disagreement you provoke but the disagreement that fails to appear where you expected it, and how do you set that expectation in advance?
• The premortem and authentic dissent both depend on someone already holding a private doubt to voice — what surfaces a shared assumption that every party genuinely, sincerely holds, with no dissenter anywhere in the room to provoke?