Seeing is believing: the direct and contingent influence of pictures in health promotion advertising.

Because pictures, compared with words, are more effective in triggering vivid imagery, their effects should increase in situations in which they play a crucial role in facilitating imagery. This study accordingly explored the relative effects of information presented in pictorial formats and verbal formats in health promotion advertising. Symptoms presented in pictorial formats increased perceptions of the severity of a disease, whereas prevention options presented in pictorial formats enhanced efficacy in preventing the disease. This study also examined two contingent situations: when people were oriented toward visual processing, and when imagery could not be easily triggered without the help of pictures, such as when symptoms or prevention options were difficult or unpleasant to imagine. The findings of three studies supported the offered predictions.