When context matters: a multilevel analysis of household and neighbourhood crowding on aggression and withdrawal

Studies examining the effects of density and crowding on human social behaviour have produced inconsistent results. This paper argues that among the reasons for these varied findings are: (1) the failure of researchers to examine how the level of density in the wider contextual environment influences the nature of the relationship between household density and social behaviour; (2) the tendency of past studies to overlook the negative consequences of both very low and very high levels of density; and (3) a lack of research investigating whether multiple coping strategies to high-density environments may be invoked by a single individual. Data from the Toronto Mental Health and Stress study are analysed using hierarchical nonlinear modelling to assess the interaction between household and neighbourhood density effects on aggression and withdrawal. The results support the notion that the effects of density on aggressive and withdrawn behaviour are nonlinear in nature and that the impact of household density is conditional on neighbourhood density. The implications of these findings for future research on density are discussed.