Here I will discuss the problem of 'Shifting Balances', on the basis of my almost thirty years of research experience in the area of environmental psychology. I refer to my long research experience, which has allowed me to grasp some important changes which I believe have taken place over the last twenty years in the sciences of the human physical environment. These changes have led to progressively different modalities of understanding the physical environment today -with regard to the human behaviour taking place in it- compared to how it was initially considered by environmental psychology and in the early scientific interests of the International Association for People-Environment Studies (lAPS). These changes seem to have been partially received by lAPS, as may be shown by the history of its acronym. M the older members are more aware of, from its founding period (starting in 1976 and ending in 1981) up until 1990, this was the 'International Association for the Study of People and their Physical Surroundings', changing after that date to the 'International Association for People-Environment Studies'. I believe that this change of name demonstrates the willingness of the Association to shift its interests regarding human behaviour in relation to the physical environment, considering this not only in a spatio-physical sense -i.e. as simple 'physical surroundings' of human behaviour- but with the more complex modalities the term 'environment' suggests today. Here I will try to discuss these changes, in order to show that the 'Shifting Balances', which are the concern of this conference, may in part be due to those changes currently taking place and not yet sufficiently assimilated by lAPS.