Australasian Mathematical Psychology Conference 2019

Exploring group decision making under ambiguity and risk

Yiyun Shou
Research School of Psychology, Australian National University
Guangqian Pan

Over thirty years ago, researchers demonstrated that an individual’s risk taking tendency could be influenced by the group to which they belonged. Some research reported a “risk shift” phenomenon where individuals became more risk seeking in a group setting. This was thought to be a result of a diffusion of individual responsibility for the decision outcomes when in a group setting. Subsequently, however, other studies revealed a “caution shift” phenomenon, where individuals became more risk averse – especially when their group had a low risk taking tendency. Given these equivocal findings, it is still unclear what drives individual’s risk taking tendency in group decision making. In addition, little is known about group decision making in situations where the information is ambiguous. This study aimed to investigate the risk/caution shift phenomena, and extend the exploration to understanding group decision making under ambiguity and how individuals may shift their attitudes toward ambiguity. An experimental study was carried out involving 20 groups comprised of 5 participants each. We compared how individuals’ preferences of risky/ambiguous choices changed before and after they engaged in group discussion. A general “caution shift” phenomenon was revealed, especially for ambiguous situations. Furthermore, most individuals converged their preferences toward the group decisions. We also explored the influence of individual difference variables, including personality traits and attitudes toward uncertainty.