This study examines how attachment styles affect business negotiations, particularly, the impasses that negotiation research has rarely investigated. Extending attachment theory to the managerial principal-agent literature, this paper explains when and why agents effectively negotiate on behalf of their principals. We experimentally primed distinct principal-agent attachments (i.e., secure, anxious, or avoidant). In the simulation, negotiators' underlying interests were incompatible-the negotiation had no actual bargaining zone. However, agents were motivated to reach a deal, which would not be in the best interest of their principals. Agents securely attached to their principals avoided ill-fated deals (at their own expense); whereas agents avoidantly attached were most likely to agree to an ill-fated deal, thereby jeopardizing their principals' interests. An analysis of participants' own descriptions of why they reached such decisions reveals that secure agents negotiated for the best interest of their principals; whereas anxious and avoidant counterparts were oblivious to the principals' underlying interests. (C) 2010 Elsevier Inc. All rights reserved.