This paper investigates how changing the value of one attribute while keeping other attributes constant influences consumers' judgments and behaviors. We find that in two options, a proportionally equal change in one attribute tilts people's preference toward the option with higher (or lower) absolute magnitude of change when the change is desirable (or undesirable). We propose that when individuals face an attribute change, they use a deliberative and effortful response, known as System 2, to detect the change. However, they rely less on this system to evaluate the changed options. Instead, a more automatic System 1 processing influences their decision by making them apply the bigger‐is‐better heuristic (bigger‐is‐worse for an undesirable change) to prefer the option with the highest (lowest) absolute magnitude of change. Six studies demonstrate this phenomenon in both lab and real settings and support our hypothesis. Copyright © 2013 John Wiley & Sons, Ltd.