Very interesting. Good advice was already given. Some stuff for further inspiration.

From there:

"...The main idea of role-oriented programming is that humans think in terms of roles. This claim is often backed up by examples of social relations. For example, a student attending a class and the same student at a party are the same person, yet that person plays two different roles. In particular, the interactions of this person with the outside world depend on his current role. The roles typically share features, e.g., the intrinsic properties of being a person. This sharing of properties is often handled by the delegation mechanism..."

"...Many researchers have argued the advantages of roles in modeling and implementation. Roles allow objects to evolve over time, they enable independent and concurrently existing views (interfaces) of the object, explicating the different contexts of the object, and separating concerns. Generally roles are a natural element of human daily concept-forming. Roles in programming languages enable objects to have changing interfaces, as we see in real life - things change over time, are used differently in different contexts, etc."

Yet another promised land. You may also take a look at the many links provided ibidem and as well at Roles represent objects that interact to achieve some purpose... by Trygve Reenskaug.

Best regards, Karl