The stimulus value of group boundaries was investigated in a field experiment. It was hypothesized that the size of a group and the status of its members would reduce the permeability of a boundary around an interacting group. Two or 4 interacting people of high or low status interrupted the traffic flow in a university hallway. Results indicate support for the hypothesis: fewer passersby walked through high status than low status groups. A control condition where wastebarrels replaced the interactors was penetrated more than either high or low status interacting groups. The author sees, in these results, support for Lyman and Scott's hypothesis that groups develop territorial boundaries, and for Milgram and Toch's hypothesis that group boundaries vary in their permeability. (Author/TL)