People fail to re-evaluate established procedures when situations change only marginally

Evidence

The set effect (Einstellung) could be seen as underlying what might be termed the ‘small increment effect’. Stated simply, in repeated runs of the Trucking Game, the participants do not bother to re-evaluate a procedure established in one circumstance when applying it to another which is only marginally different. If on one occasion I lent you £100, and you paid it back as you said you would, then I am quite likely to see a loan of £125 as essentially the same transaction. — Diego Gambetta, Trust - Making and Breaking Cooperative…, 696

Categorization

• XREF: Small-increment effect parallels how trust formed under observation erodes imperceptibly as constraints slacken — directly relevant to blindness-removes-observability arc. — connects to: Caseload reductions only change practice past a threshold, so small cuts do nothing; Routine processing silently subverts stated policy by reproducing prior patterns of advantage. — Michael Lipsky, Street-Level Bureaucracy: Dilemmas of…, 624