Foreground:background salience:: Explaining the effects of graphical displays on risk avoidance

The purpose of this research was to determine the mechanisms underlying the graphical effect identified by Stone, Yates, and Parker (1997), in which graphical formats for conveying risk information are more effective than numerical formats for increasing risk-avoidant behavior. Two experiments tested whether this graphical effect occurred because the graphical formats used by Stone et al. highlighted the number of people harmed by the focal hazard, causing the decisions to be based mainly on the number of people harmed (which we label the "foreground") at the expense of the total number of people at risk of harm (which we call the "background"). Specifically, two graphical formats were developed that displayed pictorially both the number of people harmed and the total number at risk, and use of these display formats eliminated the graphical effect. We thus propose that the previously discussed graphical effect was in fact a manifestation of a more general foreground: background salience effect, whereby displays that highlight the number of people harmed at the expense of the total number of people at risk of harm lead to greater risk avoidance. Theoretical and practical implications are discussed. (C) 2003 Elsevier Science (USA). All rights reserved.