When information security depends on font size: how the saliency of warnings affects protection behavior

Prior research on how to improve the effectiveness of information security warnings has predominantly focused on either the informational content of warnings or their visual saliency. In an online experiment (N = 1'486), we disentangle the effect of both manipulations and demonstrate that both factors simultaneously influence decision making. Our data indicate that the proportion of people who engage in protection behavior can be increased by roughly 65% by making a particular warning message more visually salient (i.e. a more conspicuous visual design is used). We also show that varying the message's saliency can make people behave very differently when confronted with the same threat or behave very similarly when confronted with threats that differ widely in terms of severity of outcomes. Our results suggest that the visual design of a warning may warrant at least as much attention as the informational content that the warning message conveys.