Handshaking Promotes Deal-Making by Signaling Cooperative Intent

We examine how a simple handshake—a gesture that often occurs at the outset of social interactions—can influence deal-making. Because handshakes are social rituals, they are imbued with meaning beyond their physical features. We propose that during mixed-motive interactions, a handshake is viewed as a signal of cooperative intent, increasing people’s cooperative behavior and affecting deal-making outcomes. In Studies 1a and 1b, pairs who chose to shake hands at the onset of integrative negotiations obtained better joint outcomes. Study 2 demonstrates the causal impact of handshaking using experimental methodology. Study 3 suggests one driver of the cooperative consequence of handshaking: negotiators expected partners who shook hands to behave more cooperatively than partners who avoided shaking hands or partners whose nonverbal behavior was unknown; these expectations of cooperative intent increased negotiators’ own cooperation. Study 4 uses an economic game to demonstrate that handshaking increased cooperation even when handshakes were uninstructed (vs. instructed). Further demonstrating the primacy of signaling cooperative intent, handshaking actually reduced cooperation when the action signaled ill intent (e.g., when the handshaker was sick; Study 5). Finally, in Study 6, executives assigned to shake hands before a more antagonistic, distributive negotiation were less likely to lie about self-benefiting information, increasing cooperation even to their own detriment. Together, these studies provide evidence that handshakes, ritualistic behaviors imbued with meaning beyond mere physical contact, signal cooperative intent and promote deal-making.