This is one of the most important issues in the approaches to ditched enclosures, especially to the big ones, that present a large time span.
At Perdigões, a set of 34 radiocarbon dates will be soon published, showing that the site lived for almost 1500 years and that its area and layout has changed through that period of time.
These kinds of programs are needed to deal with sites that have long duration, avoiding the traps of dealing with them as a whole. Did Perdigões started as a small Neolithic enclosure that gradually grew? Well, the actual data seems to suggest so. But that suggestion needs confirmation, because outer ditches still to be excavated and dated.
Nevertheless, the actual available radiocarbon and archaeological data clearly shows that there is a long biography of Perdigões. To understand the site’s social role (or social roles) is to understand that biography.