This document discusses research in the context of four basic issues in the area of crowding and personal space. The research upon which the author draws is from a series of three laboratory studies of the effects of manning levels on group experiences, performance, and verbal interaction. In these studies, groups of male college students worked on a task which required: (1) fewer than the number of persons present over-manning); (2) precisely the number of persons present (adequate manning); and, (3) more than the number of persons present (undermanning). The four issues relating to this research are discussed, and the theoretical developments which evolved are reviewed. (Author/PC)