The reason a concession invites a concession

A seller drops the price by ten per cent. The buyer, who had no intention of changing their position, offers to shorten the payment terms. Nobody asked them to. The movement of one party created a felt obligation in the other to move as well.

What everyone sees

The buyer’s concession looks like a calculated response: the seller moved, so the buyer meets them partway. Calculation may be present, but the primary driver is not arithmetic — it is the social norm of reciprocity, which operates whether or not the buyer has done the calculation.

What is actually happening

Gouldner described the norm of reciprocity as a universal social mechanism: a benefit received creates an obligation to return one. Cialdini’s door-in-the-face technique relies on the same norm: an initial large request followed by a smaller one converts the retreat into a concession, which triggers reciprocal concession. Pruitt found that reciprocal concession-making is one of the strongest predictors of reaching agreement. The mechanism is not strategic matching; it is the felt discomfort of receiving movement without returning it, which social norms treat as an unpaid debt.

Why it stays hidden

The norm hides because the buyer experiences their own concession as voluntary. They do not feel pressured; they feel fair. The fairness is real — reciprocity is a genuine social norm — but it is the norm that produced the movement, not an independent assessment of the terms. If the seller had not moved, the buyer would not have offered the shorter payment terms, which demonstrates that the concession was induced by the norm rather than by the value of the deal.