The unit bias, which asserts that consumption decreases as a food unit size decreases, is a prominent effect studied in psychology, health, and obesity research domains; yet, little is known about when or why this effect occurs, or how marketing plays a role in the effect. This research extends the current understanding of the unit bias by proposing the Social Unitization Effect (SUE), which posits that consumers’ selection of discrete unitized foods is dependent on impression management motives. That is, when impression management motives are low, consumers choose a greater number of small (vs. large) food units; however, in social (public) settings, when impression management motives are higher, this difference between small and large food units selected is attenuated. This is driven by a reduction in the number of small units selected when consumers are with others (vs. alone). We also demonstrate how the SUE manifests in various marketing contexts via factors like servicescape design (e.g., in-store surveillance), food branding (e.g., branding food as ‘mini’), and food design (i.e., the shape of food).
