Scrum teams strive to create an atmosphere where people can enjoy the process of producing excellent work yet still meet business goals and remain profitable. Getting a team to a level where this is possible is often a struggle, but with management support Scrum teams can reach a high-performing, rich mix of fun and accountability and can often out-deliver their peer teams.
The chemistry the team has created, however, is fragile. Its culture and ability to deliver effectively can be thrown off balance when someone is added to the team in the middle of a project that has not been part of the cultural growth of the team. They are bringing in the company culture, which can lead to the perception of social deviance.