The group-contagion effect: the influence of spatial groupings on perceived contagion and preferences.

We used contagion theory as a framework for studying the influence of spread of qualities in a group. We found that people's preferences change depending on how objects are arranged in a group. They prefer to choose from a closely arranged group if one unidentified object in that group has a positive quality, but prefer to choose from a group in which objects are farther apart if one unidentified object in that group has a negative quality. We call this pattern of preference the group-contagion effect. We also found that the magnitude of the effect increases if the number of objects possessing the positive or negative quality increases.