Switching dynamics in an interpersonal competition brings about "deadlock" synchronization of players

In competitive sport game behavior, certain interpersonal patterns of movement coordination evolve even though each individual player only intends to exert their own strategy to win. To investigate this interpersonal pattern formation process, we asked pairs of naïve participants to engage in a play-tag game in which they had to remove a tag fastened to their partner's hip. Relative phase analysis of the players' step towards-away velocities indicated that anti-phase synchronization evolved across 10 repetitions of the game. We clarified evolution of this synchronization process using a dynamical model with an attractor (at relative π phase) and a repeller (at 0 relative phase) and discuss the self-organized nature of model and its ability to embody general solution for martial art interpersonal coordination.