Fig 1. An example of triadic coordination dynamics.

Coordination among three agents (labeled as 1, 3, and 4) is shown as the dynamics of two pairwise relative phases (A) and three instantaneous frequency trajectories (B). Around 10s, three agents formed an all-inphase relation (ϕ_1,3 ≈ ϕ_3,4 ≈ 0 rad) for a few seconds, marked by a black bar on the left in (A). This pattern recurred intermittently two more times (middle, right bars in A), which ended when pair 3–4 switched to antiphase (40–48s, orange trajectory ϕ_3,4 ≈ π rad). Both relative phase trajectories (A) evolve on a slow time scale because the frequencies of these three agents are very close (B).