Bottoms Up! The Influence of Elongation on Pouring and Consumption Volume

Abstract

Although the effects of shapes on area perceptions have been widely investigated, we replicate, extend, and generalize one of the few studies to relate the effects of shapes to consumption volumes (Raghubir and Krishna 1999). While Raghubir and Krishna demonstrate the effect of the elongation of prepoured drinks on consumption volume, we have people pour their own drinks in a series of controlled field experiments. Two experiments in cafeterias show that both children and adults pour and consume more juice when given a short, wide glass compared to those given a tall, slender glass, but they perceive the opposite to be true. We conclude that the elongation of glasses negatively influences consumption volume in a single-serving context. A third potentially policy-relevant field experiment conducted with Philadelphia bartenders and liquor shows that the effect of elongation is moderated—but not eliminated—with pouring experience.