Rood screens and the medieval clerical-laity divide

In a recently broadcast documentary on ARTE, I learned about an architectural element in medieval Christian churches that is rarely seen today: the rood screen. This element, which visually and physically separated the clerical space of the choir (the area around the altar) from the nave occupied by lay worshippers, caught my interest and led me to do further research into the social and theological aspects that prevailed in medieval churches. I discovered that medieval Christianity was very different from what is practiced today. Instead of a participatory approach, in which all believers actively participate in worship, there was a clear separation between clergy and laity. Rather, medieval Christianity was hierarchical and exclusive in character, with the relationship between clergy and laity characterized by distance and dependence. Here is a brief summary of what I have been able to find out so far.