Who achieves the best negotiated outcomes: strangers, friends, or romantic partners? In a 1993 negotiation simulation, Margaret Neale of Stanford University and Kathleen McGinn found that pairs of friends achieved higher joint gains than married couples and pairs of strangers.

Along with their colleague Elizabeth Mannix of Cornell University, the researchers suggest that a “curvilinear relationship” exists between the strength of the tie between negotiating partners and the gains they achieve. Specifically, negotiating friends and couples have an edge over strangers by virtue of their knowledge of the other side’s preferences. Yet couples may be so averse to conflict that they are less successful than friends at capitalizing on differences.