Dynamics of improvising together.

In a previous life (when I was a 30-something) I frequently participated in dance improvisation sessions sponsored by either the Univ. of Wisc. Dance Department or local dance groups. One of the basic exercises was 'mirroring', two dancers generating novel movements by attempting to spontaneously generate matching movements. This worked much better when participants were equal, rather than one being designated the leader. Here is an interesting bit of work by Noy et al. describing why that was the case:

Joint improvisation is the creative action of two or more people without a script or designated leader. Examples include improvisational theater and music, and day-to-day activities such as conversations. In joint improvisation, novel action is created, emerging from the interaction between people. Although central to creative processes and social interaction, joint improvisation remains largely unexplored due to the lack of experimental paradigms. Here we introduce a paradigm based on a theater practice called the mirror game. We measured the hand motions of two people mirroring each other at high temporal and spatial resolution. We focused on expert actors and musicians skilled in joint improvisation. We found that players can jointly create novel complex motion without a designated leader, synchronized to less than 40 ms. In contrast, we found that designating one player as leader deteriorated performance: The follower showed 2–3 Hz oscillation around the leader's smooth trajectory, decreasing synchrony and reducing the range of velocities reached. A mathematical model suggests a mechanism for these observations based on mutual agreement on future motion in mirrored reactive–predictive controllers. This is a step toward understanding the human ability to create novelty by improvising together.