What Causes The Description-Experience Gap? A Drift-Diffusion Model Analysis

When faced with a choice between two monetary lotteries, people make different decisions depending on whether they rely on their personal experience or upon described information. In the study of risky decision making, this discrepancy has been the called description-experience gap. While this phenomenon is well-established, there is still ongoing academic debate about the underlying causes of the effect. Using the drift-diffusion model, we investigate how components of decision making change when participants receive feedback about the outcomes to their choices. Our findings show that the description-experience gap is associated with shifts in drift rate and boundary separation, suggesting that individuals adjust their evaluation methods and response caution after experiencing outcomes. Notably, we found no evidence that shifts in starting point contribute to the description-experience gap, indicating that pre-evaluation biases do not play a role. Additionally, our analysis introduces three subcategories to the description-experience gap that distinguish between how existing choice preferences change due to feedback. Our results suggest that different dynamics might be at play depending on whether an existing preference increases or weakens. We find that in decision problems where an existing preference intensifies, the drift rate is, in about half of the cases, the sole parameter facilitating the description-experience gap. In contrast, in decision problems where an existing preference weakens, boundary separation is, also in about half of the cases, the only parameter causing the gap.