How many laypeople holding a popular opinion are needed to counter an expert opinion?

In everyday situations, people regularly receive information from large groups of (lay) people and from single experts. Although lay opinions and expert opinions have been studied extensively in isolation, the present study examined the relationship between the two by asking how many lay people are needed to counter an expert opinion. A Bayesian formalisation allowed the prescription of this quantity. Participants were subsequently asked to assess how many lay people are needed in different situations. The results demonstrate that people are sensitive to the relevant factors identified for determining how many lay opinions are required to counteract a single expert opinion. People’s assessments were fairly good in line with Bayesian predictions.

  • Hornikx, J., Harris, A., & Boekema, J. (2018). How many laypeople holding a popular opinion are needed to counter an expert opinion? Thinking and Reasoning, 24 (1), 117-128.

Cultural differences in the perceptions of strong and weak arguments

The process of arbitration requires human reasoning and decision-making. Parties evaluate the evidence that is available to them and decide how to best present their case. Arbitrators aim to resolve a dispute by weighing the evidence and the legal arguments that are presented by each side. Researchers have underlined the importance of strong evidence in legal deliberations, but what exactly characterizes strong arguments? This chapter addresses this question as a first point. The characteristics of arbitrators, such as age, gender, and cultural background, may affect how arbitrators process arguments. Yet given the aim of arbitration to be an objective and neutral process, it is important to consider how such characteristics may impact the ultimate outcome of a case. This chapter examines the last of these characteristics, namely the role of culture in this decision-making process. More precisely, this chapter reviews the research evidence on how members of different cultures evaluate strong and weak arguments.

  • Hornikx, J.  (2017). Cultural differences in the perceptions of strong and weak arguments. In T. Cole (ed.), The role of psychology in international arbitration (pp. 72-92). Alphen aan den Rijn: Wolters Kluwer. [link]