April 23, 2016
People who sing in a choir have perhaps experienced it: singing together not only synchronizes the singers' breathing but also their heart rate. Such synchronization effects can also be observed in couples. They frequently occur unconsciously – those affected are completely unaware of the convergence of these physiological responses. They do, however, feel a sense of connectedness and belonging.
Sebastian Wallot from the Max Planck Institute for Empirical Aesthetics, together with a group of Danish scientists, has studied this phenomenon in greater depth. To do this, the researchers conducted an experiment in which groups of three people were required to perform a task that involved teamwork: they were asked to build as many origami boats as possible within a specified period of time. The teams worked in an assembly-line manner and divided up the folding tasks between the various team members. After a while, the groups were allowed to decide whether they wanted to try out a new folding technique for the remaining time or whether they wanted to stick with the old method. At the end, the participants completed a questionnaire, reporting how connected they felt to their group and how they found the cooperation.
Throughout the experiment, the researchers measured the participants' arousal and emotions using various physiological parameters: heart rate, skin conductance and the activity of two facial muscles. Each of these parameters is an indicator for positive and negative emotions.
The result: the activity of the zygomaticus major, a facial muscle that plays an important role in smiling, and skin conductance, an indicator of arousal, synchronized in members of a team. This is a sign that they were experiencing positive emotions together and were stressed or relaxed as the case may be. And there's more: the better the cooperation, the more harmonized the muscle activity. The researchers were even able to use the data to predict what decision the participants would make. Groups with a high level of synchrony in muscle activity tended to be satisfied and frequently chose to retain the tried-and-tested folding technique. Groups with lower synchrony opted more frequently for a change. Another interesting finding was that, irrespective of how the groups worked together previously, the synchrony usually declined if the new method was adopted. Learning the new technique thus disrupted the harmony of physiological responses. However, negative synchronization effects were also noted: if skin conductance, a measure of mental tension and stress, showed a high level of synchronization between the team members, this tended to be an indication of problems within the group.
When it comes to the details, however, the dynamics are more complicated. Other experiments are therefore needed to study how precisely the various parameters develop, depending on the behaviour and mood of the group. Previous research already shows, however, that the synchrony of physiological responses can be a benchmark of connectedness within a team.