"A deviant is willing to publicly point out flaws in the current strategy, along with possible repercussions. By doing so, the deviant forces the other members of a team to defend the current direction, and possibly to explore alternative paths.
Someone willing to act as the team deviant is difficult to find, since the required behavior goes against the close-knit nature of an effective group. Also, there may be peer pressure to keep quiet, especially if a re-evaluation of the team’s direction could slow down completion of the expected deliverable or impose additional costs. Consequently, the team leader needs to be quite supportive of this person’s activities, particularly in regard to shielding him from the negative comments of the rest of the team."
Steven M. Bragg