Change perception at zero tolerance: How protected values bias sensitivity to social improvement.

Across six experiments, we examined how sensitivity to change varies with protected values (PVs). In Experiment 1, vegetarians were less appreciative than meat-eaters of large (but only partial) reductions in other people's meat consumption, but they were more appreciative than meat-eaters of smaller but absolute reductions (i.e., reduction to zero meat consumption). In Experiment 2, a similar pattern emerged in political groups: Republicans, who value immigration control more than Democrats, were relatively less sensitive to large but partial reductions in illegal immigration than to its elimination; the reverse pattern was observed for gun possession. In Experiment 3, we manipulated participants' values regarding child labor. Individuals who generated arguments in defense of child labor held less protected values and were comparatively more sensitive to change in child labor numbers. Further studies showed that protected values make people focus on the outcome (i.e., the present state) more than on the trajectory of change (i.e., the difference from the past; Experiment 4) and that they inspire stricter thresholds for what is considered acceptable (Experiment 5). Experiment 6 shows that protected values cause a heightened sensitivity to absolute changes to zero, rather than insensitivity to changes overall. These findings indicate that protected values amplify sensitivity to absolute changes to zero, compared to partial changes-even larger ones-that fall short of zero. The results have theoretical implications for theories of progress perception and quantity (in)sensitivity. (PsycInfo Database Record (c) 2026 APA, all rights reserved).