Conversational Principles in Cognitive Biases: The Case of Overprecision in Interval Estimation

Conversational principles such as Grice’s maxim of Quantity (roughly: be informative) are essential to our ability to communicate efficiently. Due to their ubiquitous nature in language-based communication, they may interfere in a large variety of other cognitive tasks which at first glance may not seem linguistic in nature. Here, we report three experiments that investigated the role of the Quantity maxim in the overconfidence bias in interval estimation (also referred to as overprecision). Experiment 1 (N = 309) used a chat paradigm to bias participants against providing the most informative answer, as would be required by Quantity, resulting in a reduced overprecision bias. Experiment 2 (N = 322) and Experiment 3 (N = 309) tested whether this effect depends on explicit social cues, specifically, the presence of a conversational partner. Both experiments replicated Experiment 1 in the absence of a full conversational context, thus showing that linguistic cues alone are sufficient. Taken together, these results suggest that conversational principles – extensively studied in linguistics, but largely ignored in research on cognitive biases – play an important role in the overprecision bias and, as we argue, likely in other biases as well.