Authentic Lithuanian Yeshiva.

A healthy yeshiva operates through no universal methods, but several general principles, and these become adapted in many specific ways. One way is culling. Any successful yeshiva has internal gatekeepers who drive out the people of lower moral standards, ability and behavior or those who are merely genetically incompatible. The sane form of this is exile; the insane form is  not doing it.

There is a side idea: Don't join a group of crazy people even if their doctrines sound nice.