Perceptual Modification of the Built Environment to Influence Behavior Associated with Physical Activity: Quasi-Experimental Field Studies of a Stair Banister Illusion

Rich Masters, Catherine Capio, Jamie Poolton, Liis Uiga

Re-engineering the built environment to influence behaviors associated with physical activity potentially provides an opportunity to promote healthier lifestyles at a population level. Here we present evidence from two quasi-experimental field studies in which we tested a novel, yet deceptively simple, intervention designed to alter perception of, and walking behavior associated with, stairs in an urban area. Our objectives were to examine whether adjusting a stair banister has an influence on perceptions of stair steepness or on walking behavior when approaching the stairs. In study 1, we asked participants (n = 143) to visually estimate the steepness of a set of stairs viewed from the top, when the stair banister was adjusted so that it converged with or diverged from the stairs (± 1.91°) or remained neutral (± 0°). In study 2, the walking behavior of participants (n = 36) was filmed as they approached the stairs to descend, unaware of whether the banister converged, diverged, or was neutral. In study 1, participants estimated the stairs to be steeper if the banister diverged from, rather than converged with, the stairs. The effect was greater when participants were unaware of the adjustment. In study 2, walking speed was significantly slower when the banister diverged from, rather than converged with, the stairs. These findings encourage us to speculate about the potential to economically re-engineer features of the built environment to provide opportunities for action (affordances) that invite physical activity behavior or even promote safer navigation of the environment.