The current project examined how changes to task constraints impacted the behavioral dynamics of an interpersonal collision avoidance task previously examined and modeled by Richardson and colleagues (2015). Overall, the results demonstrate that decreasing the cost associated with colliding influences the stability and symmetry of the movement dynamics observed between co-actors in a manner consistent with those predicted by the Richardson et al. (2015), collision avoidance model. The current study therefore provides evidence that the behavioral dynamics that shape interpersonal or joint-action behavior are not only defined by the physical and informational properties of a task, but also by the strength and importance of the shared task goal.