In recent years, conceptualizations of the human crowding phenomena have developed from simple deterministic ones to those that emphasize the interaction of environmental, social, and personal variables. Furthermore, the influences of many variables suspected to mediate the density response relationship have been empirically tested in a variety of settings. It must be recognized, however, that the results of these tests may be setting specific and may not generalize to other setting types. The present study examines the influence of the social relationship between occupants, perceived similarity, formal group structure, and previous residential experience on the association between household density and attitudinal, behavioral, and health measures of well-being. The results of a survey analysis suggest that household density does have effects on satisfaction and behavior; however, no health effects were found. Furthermore, these reactions to density are exacerbated when the social relationship between occupants is close and when individuals have a history of high density living conditions. Although some results seem counterintuitive, they can be explained by adopting a dynamic casual model of crowding.