Explanations

When people exchange knowledge, both truths and falsehoods can proliferate. We study the role of explanations for the spread of truths and falsehoods in 15 financial decision tasks. Participants record the reasoning behind each of their answers with incentives for accuracy of their listeners’ responses, providing over 6,900 unique verbal explanations. A separate group of participants either only observe one orator’s choice or additionally listen to the corresponding explanation before making their own choice. While listening to explanations improves average accuracy, there is substantial heterogeneity: explanations enable the spread of truths, but do not curb the contagion of falsehoods. To study mechanisms, we extract every argument provided in the explanations alongside a large collection of speech features. The largest part of the asymmetry reflects how the reasoning is expressed: explanations for truths are richer - more detailed, structured, and articulated - than those for falsehoods, and receivers imitate richer explanations more regardless of whether the answer is correct. This richness gap accounts for about 60% of the asymmetric benefit. A mechanism experiment shows that varying linguistic richness exogenously increases imitation, even among explanations that independent human annotators judge to contain identical arguments.