The effect of package shape on consumers' judgments of product volume: Attention as a mental contaminant

A series of experiments examined how a container's shape can bias judgments of product quantity. Packages that have shapes that are perceived as attracting more attention are also perceived to contain a greater volume of a product than same-sized packages that attract less attention. The disparity in attention leads to "mental contamination" of the volume judgment. The bias holds for different sets of containers, for containers placed in different contexts, and for containers with contents varying in desirability. Habituation to an unusual container that attracts attention can reduce the effect, as can viewing containers with a disliked content.