When people find themselves in difficult conflicts , they often turn to mediation( 调解 ) . Mediators are advised to listen attentively , avoid favoring the ideas of one party , and make both sides feel at ease.Surprisingly , new research that my colleagues and I conducted suggests that , to effectively help people settle their conflicts , mediators should adopt a hostile( 敌对的 ) attitude rather than a calming one.A hostile mediator , we find , brings better results than a nice one. Why would adding more negativity( 消极性 ) to an already hostile situation prove beneficial ? Consider how parents typically react when they can ’ t get their children to stop quarreling : “ I don ’ t care who started it—both of you , go to your rooms ! ” At first sight , a calm mediator seems likely to be more effective.But as anyone with brothers or sisters knows , parents ’ seemingly unsympathetic treatment of the situation can have an unusual effect.Children who moments before were troubling each other suddenly become more reasonable due to their unkind parents. In our research , we created situations in which pairs of negotiators were part of a heated conflict.In some cases , the mediator had a “ nice ” approach—calm and polite.In others , he was hostile—aggressive and somewhat rude.Across different types of conflicts , we found that negotiators were more willing and able to reach an agreement in the presence of a hostile mediator than in the presence of a nice one. The main result of the test is not that hostility pays off.In fact , recent research has documented the social costs of negative behavior.For example , being the target of rude behavior reduces people ’ s performance on a variety of tasks.Other research shows the social benefits of positive behavior.People are more likely to close deals and become future business partners. Even with the widespread social benefits of positive behavior and costs of negative behavior , hostility can pay off in certain situations.