The presence of variety reduces perceived quantity

Against common intuition, we find that variety in an assortment reduces its perceived quantity. Two studies show that people provide larger quantity estimates when shown random patterns of identical colored dots or geometric shapes than when those patterns contain variety. The difference in perceived quantity does not grow as the number of different types increases beyond two, and it disappears if the overall area occupied by the set is made salient through context. We attribute the results to the natural consolidation of identical items into a single Gestalt whole that makes the set seem larger. Two additional studies show that this perceptual influence also causes people to pour more when using varied items to match a sample of food. The article closes with a discussion of the potential implications of these findings for variety research and portion control.