Why are some group and team members willing to socially loaf on work assignments? What as a manager could you do to tactfully correct this behavior (elaborate with specifics)?

You are a manager, and a member of one of your task groups comes to you and says that their group is engaging in groupthink and she/he is being pressured to conform to their rules. You cant disclose this information to anyone, yet you want to discourage this groups cohesiveness. What would you do?

Why are some group and team members willing to socially loaf on work assignments? What as a manager could you do to tactfully correct this behavior (elaborate with specifics)?