Groups often outperform individuals in problem-solving. Nevertheless, failure to critically evaluate ideas risks suboptimal outcomes through so-called groupthink. Prior studies have shown that people who hold shared goals, perspectives, or understanding of the environment show similar patterns of brain activity, which itself can be enhanced by consensus-building discussions. Whether shared arousal alone can predict collective decision-making outcomes, however, remains unknown. To address this gap, we computed interpersonal heart rate synchrony, a peripheral index of shared arousal associated with joint attention, empathic accuracy, and group cohesion, in 44 groups (n = 204) performing a collective decision-making task. The task required critical examination of all available information to override inferior, default options and make the right choice. Using multidimensional recurrence quantification analysis (MdRQA) and machine learning, we found that heart rate synchrony predicted the probability of groups reaching the correct consensus decision with >70% cross-validation accuracy-significantly higher than that predicted by the duration of discussions, subjective assessment of team function or baseline heart rates alone. We propose that heart rate synchrony during group discussion provides a biomarker of interpersonal engagement that facilitates adaptive learning and effective information sharing during collective decision-making.

Groups often outperform individuals in problem-solving. Nevertheless, failure to critically evaluate ideas risks sub-optimal outcomes through so-called groupthink. Prior studies have shown that people who hold shared goals, perspectives or understanding of the environment show similar patterns of brain activity, which itself can be enhanced by consensus building discussions. Whether shared arousal alone can predict collective decision-making outcomes, however, remains unknown. To address this gap, we computed interpersonal heart rate synchrony, a peripheral index of shared arousal associated with joint attention, empathic accuracy and group cohesion, in 44 groups (n=204) performing a collective decision-making task. The task required critical examination of all available information to override inferior, default options and make the right choice. Using multi-dimensional recurrence quantification analysis (MdRQA) and machine learning, we found that heart rate synchrony predicted the probability of groups reaching the correct consensus decision with greater than 70% cross-validation accuracy-significantly higher than that predicted by the duration of discussions, subjective assessment of team function or baseline heart rates alone. We propose that heart rate synchrony during group discussion provides a biomarker of interpersonal engagement that facilitates adaptive learning and effective information sharing during collective decision-making.

Head-mounted displays enable social interactions in immersive virtual environments. However, it is yet unclear whether the technology is also suitable for collaborative work between remote group members. Previous research comparing group performance in nonimmersive computer-mediated communication and face-to-face (FtF) interaction yielded inconsistent results. For this reason, we set out to compare multi-user immersive virtual reality (IVR), video conferencing (VC), and FtF interaction in a group decision task. Furthermore, we examined whether the conditions differed with respect to cognitive load and social presence. Using the hidden profile paradigm, we tested 174 participants in a fictional personnel selection case. Discussion quality in IVR did not differ from VC and FtF interaction. All conditions showed the typical bias for discussing information that was provided for all participants (i.e., shared information) compared with information that was only disclosed to individual participants (i.e., unshared information). Furthermore, we found that IVR groups showed the same probability of solving the task correctly. Social presence in IVR was reduced compared with FtF interaction; however, we found no differences in cognitive load. In sum, our results imply that IVR can effectuate efficient group behavior in a modern working environment that is characterized by a growing demand for remote collaboration.