Sales · Regan's soft-drink experiment (Cornell, 1971), In a now-classic study published in the Journal of Experimental Social Psychology, Dennis Regan placed subjects in a supposed art-appreciation experiment alongside a confederate, "Joe". During a break, Joe sometimes returned with two Coca-Colas and spontaneously offered one to the subject. Later, he asked the subject to buy raffle tickets. Result: subjects who had received the drink bought on average twice as many tickets, the favour received predicting compliance far better than liking. The study establishes that the norm of reciprocity creates an obligation to return that weighs more heavily than affinity, the direct foundation of the RECIPROCITY Technique in sales negotiation.
Political · The reciprocal concessions of Camp David (1978), At the Camp David accords, President Jimmy Carter orchestrated a sequence of exchanged concessions between Anwar Sadat and Menachem Begin. Israel returned the Sinai and its territorial sovereignty; Egypt offered recognition and security guarantees in return, an exchange of items of different natures, sovereignty for security. Each concession called for the next and gradually built trust. Neither party came away fully satisfied, the mark of a good agreement. The case illustrates how reciprocity, supported by a mediator and a single working text, can untangle a conflict deemed intractable.
Diplomatic · The diplomatic credit of a supporting vote at the UN, In multilateral practice, a State regularly grants its vote to a resolution championed by a partner on a matter that does not directly engage it. This support given without immediate counterpart is an investment: it creates a store of reciprocity to be drawn on when the giver, in turn, needs backing on a priority text. This logic of "credit" structures voting alliances at the United Nations and in regional forums. It shows that the RECIPROCITY Technique also operates on a deferred basis: the debt contracted today becomes a lever of influence tomorrow, provided the partner honours the norm.
Judicial · The opening concession in mediation, In civil mediation, a claimant who immediately agrees to drop an ancillary claim, for instance late-payment interest, makes an opening gesture that frequently triggers a counter-concession from the opposing party on the principal. This mechanism, documented by the work on reciprocal concessions (Cialdini, 1975), is observed in amicable-settlement processes: the visible first step creates normative pressure to respond with an equivalent step. The mediator often exploits this lever by inviting each party to "give a sign" at the start of the session, knowing that reciprocity tends to set the dynamic of compromise in motion.
Business · Cialdini's door-in-the-face (1975), Robert Cialdini and colleagues had assistants approach passers-by on a campus, presenting themselves as staff of a juvenile detention centre. They first made an extreme request, to chaperone young offenders voluntarily two hours a week for two years, which was systematically refused. They then retreated to a modest request: to accompany these young people on one afternoon at the zoo. This apparent retreat is perceived as a concession the subject feels bound to reciprocate by agreeing. The acceptance rate tripled compared with the modest request made on its own. In business, this variant of reciprocal concessions structures anchoring negotiations: ask for a lot, then retreat to obtain the essential.
Everyday life · The free sample at the market, At a market or in a supermarket, the stall offering a free tasting achieves a markedly higher purchase rate than one that merely displays the product. The passer-by who accepts the piece of cheese or the glass of wine contracts a micro-debt that they most often settle by buying, even though nothing legally obliges them to. This everyday device is the most visible application of the norm of reciprocity: a modest and sincere gesture is enough to tip the purchasing disposition. Time pressure, the stall will not stay, reinforces the effect by preventing any deferral of the response to the favour received.
