Increased knowledge of social and spatial influences on the behaviour of laboratory rats is important for both psychological and pharmacological research. This thesis investigates some housing parameters and demonstrates ways in which these variables can affect the results of behavioural tests and their interpretation in both general psychology and psychopharmacology. Popular single subject behavioural procedures used in housing studies are adapted to elucidate the effects of the cage environment on both individual and group behaviour. In the psychopharmacological context control of, and elaboration upon, social and spatial characteristics of three environments (cage, post-injection, test) may promote a more realistic approach to the study of psychotropic drug effects on animal, and ultimately, human behaviour.