Name: Justin Sukernek

Master’s Thesis Defense Meeting

Date: Friday, May 14, 2021

Time: 11:00am

Location: https://bluejeans.com/431128614/3531

Advisor: Rick Thomas, Ph.D. (Georgia Tech)

Thesis Committee members:

Rick Thomas, Ph.D. (Georgia Tech)

Chris Hertzog, Ph.D. (Georgia Tech)

Chris Wiese, Ph.D. (Georgia Tech)

Title: Examining Social Influence’s Effect on Decision-Making and Bayesian Truth Serum

Abstract: Decision-making—whether individual or in groups—can be subject to revision based on social influence, often pulling one’s opinions towards the apparent consensus (Mason, Conrey, & Smith, 2007).  Social influence has been shown to damage the effectiveness of wisdom of the crowd, suggesting that perhaps the crowd is wise—but only when the members do not interact with each other (Lorenz, Rauhut, Schweitzer, & Helbing, 2011).  An interesting, unexplored method to study the effect of social influence would be to apply it to the Bayesian truth serum (BTS), a multi-faceted measure of judgment ability (Prelec, 2004).  In its pure application, the truth serum is both a measure of judgment and a way to increase truth-telling and information quality, but currently it is unclear if social influence may have a positive or negative effect on the serum’s effectiveness.  I conduct a multi-experiment study to elucidate further the possible adverse effects of social influence, and test Bayesian truth serum’s robustness when combined with the influence of others’ opinions.  In combination, the five experiments show evidence for social influence disinforming participants; this disinformation effect appears to be detrimental to the Bayesian truth serum.  Finally, these experiments cast doubt on the Bayesian truth serum’s predictive ability in several different task contexts.  Additionally, in one experiment we find evidence that disagreeing with social influence improves reasoning ability.  Overall, this study contributes to the social influence, disinformation, and BTS literatures.