The Shift Towards Automaticity: How Time Pressure and Stress Influence Complex Decisions

Grounded in Dual Process Theories, decision-making involves automatic (System 1) and reflective (System 2) processes. While our prior work showed that framing choices as important makes complex decisions less automatic, this study explores conditions that reverse this. We hypothesise that cognitively demanding contexts shift decisions toward automaticity, increasing susceptibility to Repetition Priming (RP). In a two-stage task, participants view four faces repeating 12, 6, 1, and 1 times, then select one face. To modulate cognition, subjects are randomly assigned to an Unspecified Task (UST: “Who do you choose?”) or Important Task (IT: “Who do you choose for an important task?”) group. We evaluate choices and response times under Temporal Limitation (countdown) and Stress (adapted Montreal Imaging Stress Task), alongside BIS-11 impulsivity assessments. Results show time pressure disrupts reflective processing, making the IT group more susceptible to RP. Although impulsivity correlated with RP susceptibility, time constraints increased susceptibility even in low-impulsivity subjects. We anticipate similar outcomes in ongoing stress experiments. These findings suggest external pressures interrupt deliberate evaluation, forcing reliance on implicit biases during complex choices.