Haptic communication optimises joint decisions and affords implicit confidence sharing

TL;DR

This study demonstrates that haptic communication enables groups to make better and faster decisions than individuals, by implicitly sharing confidence through sensorimotor interactions, without explicit verbal communication.

Contribution

It shows that haptic coupling allows implicit confidence sharing and improves group decision accuracy and speed compared to explicit communication methods.

Findings

Haptically coupled dyads outperform individuals in perceptual tasks.

Dyads are five times faster with haptic communication than with explicit communication.

Dyads modulate movement timing and force to share confidence implicitly.

Abstract

Group decisions can outperform the choices of the best individual group members. Previous research suggested that optimal group decisions require individuals to communicate explicitly (e.g., verbally) their confidence levels. Our study addresses the untested hypothesis that implicit communication using a sensorimotor channel -- haptic coupling -- may afford optimal group decisions, too. We report that haptically coupled dyads solve a perceptual discrimination task more accurately than their best individual members; and five times faster than dyads using explicit communication. Furthermore, our computational analyses indicate that the haptic channel affords implicit confidence sharing. We found that dyads take leadership over the choice and communicate their confidence in it by modulating both the timing and the force of their movements. Our findings may pave the way to negotiation technologies using fast sensorimotor communication to solve problems in groups.