Balance theory is tested by repeated analysis, for four suceeding years, of the matrix of interpersonal relations among the residents of a new 320-man dormitory. As the usual static consideration of balance predicts, students recognize and like others who are near them, both in physical distance (proximity) and in college class (peership). Most important, however-if little tested-are the dynamic aspects of balance whose evaluation requires tracing individual pairs through time. Doing this shows that between room-mates and others living near to one another, attraction changes less when it is initially high; between those more distant, attraction changes less when initially low. Thus, for everyone, attraction is more stable. Over the dormitory's first four years, similitary of physical location and of college class continues to predict attraction; but between more proximate persons, prediction declines in later years, as frienships increasingly span distance and class.