Two heads are better than one: Investigating the benefits of interaction in collaborative decision making

Groups often outperform individuals in cognitive tasks. However, there is little consensus on the cognitive mechanisms that underlie effective teamwork. The present investigation examines whether the process of group interaction plays a critical role in enhancing collective performance. In the first three experiments, participants answered general knowledge questions either in pairs that were allowed to discuss and collaborate, or individually. Individual responses were used to construct nominal groups using a range of established aggregation policies. In all cases, interacting groups consistently outperformed all nominal group variants, suggesting that the advantages of group cognition stem not only from the increased knowledge pool, but from the interactive process itself. A fourth experiment extended this approach to the domain of misinformation detection—an area of pressing real-world concern—revealing a more complex pattern and pointing to potential limits in the generalizability of interaction benefits across task domains. These findings demonstrate the importance of fostering interaction in collaborative settings, where shared reasoning and metacognitive exchange can significantly improve collective decision-making.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Psychology

Grantor

University of Illinois Urbana-Champaign

Year dc:date

2025

Author dc:creator

• Unal, Belgin

Contributors dc:contributor

• Benjamin, Aaron S.
• Benjamin, Aaron S
• Sahakyan, Lili
• Dell, Gary
• Zhang, Bo
• Gupta, Pranav

• Metacognition
• Group Decision Making
• Interaction
• Collaborative Cognition

Statement dc:rights

• Copyright 2025 Belgin Ünal

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/130120

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F130120