Sales · The incidental similarity that closes the sale (Burger research, 2004), The study by Jerry Burger and his colleagues (Santa Clara University) tested, under real conditions, the effect of a simple commonality. When a solicitor led a participant to believe they shared a birth date or a first name, the acceptance rate for a request rose from 34% to 62%. Transposed to commerce, this result illuminates a common selling practice: discovering and naming a proximity (same region, same club, same school) before presenting an offer. The common ground acts as a shortcut to trust that favourably predisposes the buyer, provided it is real and not fabricated.
Political · Camp David 1978: the grandchildren's photographs, On the thirteenth day of a summit on the brink of collapse, Menachem Begin asked Jimmy Carter to autograph a photograph of the three leaders for his grandchildren. Carter had their first names looked up and personalised each print by name. As he read aloud each grandchild's name, Begin, moved to tears, spoke of what he would bequeath to that generation. This grandfather's common ground, the love for one's descendants, the future one leaves them, reopened the dialogue: « Why not try one last time? ». The Camp David Accords were signed shortly afterwards. The lever was not an argument, but a shared humanity.
Diplomatic · The personal relationship as a precondition to substance, High-level diplomacy institutionalises common ground: dinners, walks and informal exchanges always precede the official negotiating tables. The avowed aim is to build a shared human territory, children, passions, common ordeals, which will make destructive confrontation more costly once the hard bargaining begins. Work on email negotiation (Morris, Nadler, Kurtzberg and Thompson, 2002) confirms the mechanism: negotiators who first exchange a few minutes of personal talk (« schmooze ») reach agreement far more often and develop more trust than those who get straight to the point.
Judicial · CEO-analyst similarity and information favouritism (PNAS, 2023), A study published in PNAS (Jung, Kim et al., 2023) showed, across thousands of earnings calls, that analysts sharing a first name or an origin with the executive obtained privileged access to information and asked more questions. This case illuminates the use, and the excesses, of common ground in regulated contexts such as the judicial or the regulated: similarity creates a measurable favouritism bias. For a negotiator, the lesson is twofold: common ground is a powerful lever of cooperation, but its exploitation can erode the impartiality expected and must remain fair.
Corporate · Schmooze or lose: five minutes that change the deal, In an inter-firm negotiation conducted by email, two MBA teams received opposing instructions: one was to get straight to the point, the other to devote a short call first to introducing themselves and finding common ground. The latter proved more cooperative, shared more information, made fewer threats and reached agreement far more often, with better-quality outcomes for both parties (Morris et al., 2002). In business, this protocol translates into a simple rule: never start a remote negotiation without a relational preliminary that establishes similarity and trust.
Everyday life · The second-hand seller and the shared passion, When buying a car or an item privately, the buyer who discovers that the seller is passionate about the same model, brand or hobby instantly creates a bond. By sincerely sharing this interest, « I've been looking for exactly this series for years », they reassure the seller, often emotionally attached to what they are selling, that the item will go to « good hands ». The seller then becomes more inclined to negotiate the price and to favour that buyer. The condition remains sincerity: a feigned passion is exposed at the first precise question.
