Is a user assigned to the Developer Role also included as a User Role?

Peder

This question is in reference to Atlassian Documentation: Managing Project Role Membership

If I add a user as a Developer role, will all permissions granted to the User role also apply to this user? I would assume so but I wan't able to find this in the documentation.

Similarly, does someone assigned to Administrator role also have Developer and User role permissions? 

unknown

The permission of a JIRA Role will entirely depends on whatever is configured in the projects JIRA Permission Scheme. In conclusion, a Developer role and User role may both "browse project" permission but the Developer may have an additional role of "Assignable Issues". The same goes for Administrator role. Your reference here is the permission scheme