Beliefs and values are passed from parents to children and reinforced by social institutions–schools, churches, businesses, and governments; they are very difficult to change./

The answer is Core.

Core beliefs are assumptions about ourselves, others, and the world. They are beliefs that are learned from our environment. We all have core beliefs and everyone's is different as they represent how and where have been raised and who or what we have been exposed to. Core beliefs are instilled in us and are very hard to change. They are assumptions we make about life and determine how we act as well as how happy or depressed we are.

an informal structure in a bureaucracy would be something like so-called "office politics". where there's a formal structure set up for the organization, but then an informal subculture as well that has a way of organizing the bureaucracy further. this can be positive because it sets up an added degree of organization, albeit informal, within the bureaucracy.