A pupillary index of susceptibility to decision biases [Registered Report Stage 1 - Protocol]

ABSTRACT: The demonstration that human decision making can systematically violate the laws of rationality has had wide ranging impact on the fields of economics and psychology. However, the cognitive processes that give rise to irrational biases are still poorly understood. In this study, we use a pupillary index to arbitrate between two predominant existing hypotheses – the hypothesis that biases result from fast effortless processing and the hypothesis that biases result from more extensive integration. While effortless processing is associated with smaller pupillary responses, more extensive integration has been shown to be associated with larger pupillary responses. Thus, we test the relationship between pupil responses and choice behavior on six different foundational decision-making tasks classically used to demonstrate irrational biases.