Good cop, bad cop, also informally called the Mutt and Jeff technique,[1] is a psychological tactic used in interrogation and negotiation, in which a team of two people take opposing approaches to the subject.
[2] One interrogator adopts a hostile or accusatory demeanor, emphasizing threats of punishment, while the other adopts a more sympathetic demeanor, emphasizing reward, in order to convince the subject to cooperate.
This sets the stage for the "good cop" to act sympathetically, appearing supportive and understanding, and in general showing sympathy (or even empathy) for the subject.
[5] When this technique is used as a negotiation tactic outside of the interrogation context, the good cop attempts to convince the counterpart to cut a deal by implying that the bad cop will return if no agreement is reached.
[6] The disadvantage of this technique is that it can be easily identified, and the "bad cop" may alienate the subject.