Concept · Cognitive Bias: Economic and consumer biases
Unit bias
Origin: Geier, Rozin & Doros, 2006
Biological Parallel
Animals exhibit unit completion bias: a lion eats an entire gazelle leg, not 73% of one. Natural packages provide stopping cues that arbitrary portions don't. Squirrels cache whole nuts and retrieve whole nuts; partial consumption is rare. These ecological units evolved as decision simplifiers—'one unit' is a clear target in ways that 'optimal kcal intake' isn't. Unit bias reflects this: we eat the plate, the package, the bottle, because completion of natural units was ancestral fullness signaling.