An excerpt from Joseph Pelrine training material about Identities: are the roles and the responsibilities. By changing someone's role and identity you change the identity of the team.
A human can have many identities and exist in multiple socially complex systems simultaneously, and the context will determine which identity dominates.
An identity, as I understood, can be a responsibility assigned to some team member, a role in the organization assigned to someone, or simply an already existing identity (personal, professional, ...).
In a system is possible to add or remove or change a responsibility, assign a role, reinforce or weaken...