During the pandemic, video conferencing has taken over the workday, and many employers emphasize the importance of having the camera turned on so staff can see each other. It feels logical that sound and image would be the optimal substitute for physical meetings – but now a new study against the fact that the video conference can instead give a worse result than a conference call.

The Carnegie Mellon University in Pittsburgh has examined collective intelligence, that is, a group’s capacity to solve a range of problems together. Previous research has shown that synchronization between participants sharpens that ability, which raises the group’s collective intelligence.

The university looked at two types of synchronization. Partly the one that is based on the experience of facial expressions – and experiences based on the voice, It is about the interaction that is not controlled by words, but how two or more people in a conversation establish an unspoken understanding there but give each other room to talk. The starting point for these markers is the experience of the tone of voice, speech rhythm, intonation and possible stress.

199 test subjects were divided into 99 pairs. 49 of them only had contact via audio, while the rest also saw each other with video. During half an hour, six tasks were performed to demonstrate collective intelligence. The video group had some success, but at the same time they were hampered by the participants not succeeding in achieving equal verbal synchronization – while the audio group succeeded in their synchronization and problem solving.

– We found that video conferencing can actually reduce collective intelligence. The reason is that it leads to the contributions to the conversation being distributed more unequally and that the vocal synchronization is disturbed. Our study underscores the importance of audio markers, which seem to be suppressed by access to video, says Anita Williams, co-author of the study at Carnegie Mellon University on her website.

People’s conversations follow an unspoken set of rules where you take turns talking, asking for the floor or standing back for someone else. The communication around this is usually subtle – from eye contact to the changes in voice mode mentioned above. However, the visual, silent markers seem to give some people an advantage where they will dominate the conversation, a problem that seems to disappear when you only have sound available. Then the regulations flow smoothly and the number is distributed evenly.