Why the last speaker wins an undecided room

Two comparable arguments are heard and a decision is taken at once. The second is favoured. Separate the two arguments by a week and the pattern reverses. Order is not a fixed advantage for either position; it is a function of what has had time to decay by the time the judgement is made.

What everyone sees

Speaking order is read as a matter of etiquette or scheduling, occasionally as a superstition about going last. The disagreement in folk advice — some insisting on first, some on last — is a sign that both are sometimes right, and that the missing variable is the timing rather than the position.

What is actually happening

Miller and Campbell varied the intervals between two opposing presentations and between the second presentation and the measurement of attitudes, and found primacy or recency depending on that arrangement: recency dominated when the second message was close to the judgement, primacy when time separated the messages and the measurement followed later. Haugtvedt and Wegener refined the account by relating order effects to how strongly the position is processed and how resistant the resulting attitude becomes. Neither treats position as decisive on its own. Both make the decay interval the operative variable, which is why the same seat in the running order can be an advantage or a liability.

Why it stays hidden

The dependence hides because meetings almost always decide immediately after the final contribution, so recency wins in nearly every observed case. The condition that would reveal the mechanism — a delay before the vote — is rare, and its rarity converts a conditional effect into an apparent law about going last.