An informal work group is a group of poeple who have common interests, language or other similarities that lead to personal relationships. These groups are friends and spend time together inside and outside of work. If an informal group views management as a threat, they will more than likely talk about that together and share ideas how to steer clear of them or bring it up to someone above them. It's important for management and lower level employees to have a good working relationship with one another so they have a cohesive and productive work environment.