The Effect of Cognitive Load and Default Nudges on Decision-Making: Experimental Evidence from a Behavioural Study

Abstract

Cognitive overload can impair professional scepticism in high-stakes contexts such as auditing. In these settings, sustaining professional scepticism is essential. Default nudges, or pre-selected options, may offset these effects by reducing cognitive demands. We conducted two online experiments to examine how cognitive load and default nudges influence professional scepticism in auditing decisions. Experiment 1 validated a dot memory task manipulation of cognitive load and identified low and high load conditions for subsequent testing. Experiment 2 embedded this manipulation in Phillips audit task, used for measuring professional scepticism in audit. Results showed that cognitive load slowed responses and reduced accuracy. Default nudges accelerated responding and improved accuracy under load, but only when aligned with the most probable response; misaligned nudges reduced accuracy. These findings suggest that defaults act as conditional scaffolds under cognitive strain, supporting judgment and decision-making in some contexts but introducing risks in others. Misaligned defaults reduced accuracy, indicating that they can exploit intuitive responding rather than enhance deliberation.