The psychological research is clear: bad events affect us much more powerfully than good events. So it stands to reason that burdens weigh more heavily upon our decision processes than do benefits. Negotiations that center around burdens can pose psychological hazards for negotiators — contentiousness, clouded judgment, suspicion, and a diminished understanding of their own interests. The result? A smaller pie of resources, for one thing. Here is a guide to help you avert the dangers.