When someone joins a team, it is quite normal that at least one person in the team takes up the role to help the newcomer learn some of the team’s ways.
It isn’t always considered important learning. The newcomer will be grateful for the support as it tells him that he’s being welcomed in the team and will ease his ability to become aware of some of the habits in the team.
But what is actually happening, is a transfer and transformation of the team’s culture.
In their everyday interactions, the team members adapt to one another and the changing context. While it can be a conscious effort, it rarely is.
Culture is the outcome of the circumstances within which a team works and seeks to perform. Efforts to shape it directly need to be integrated by the team who reacts to their interpretations of these efforts and expectations.