This project’s main goal is to advance the field of human-robot interaction, specifically with robots that can adjust to natural interaction rhythms, while engaged on a joint task. Robots capable of open-ended and engaging interactions are useful: as learners, with humans as instructors (e.g. by demonstration, by imitation), as teachers, and as assistants of the elderly, or disabled. Mounting evidence shows that seamless timing of turn-taking–and the capability for dynamic control of a turn-taking rhythm–is associated with perceived quality and learning outcomes, in adult-adult, and in human-robot social exchanges. Moreover, in infancy, turn-taking dynamics predict emotional, social, and cognitive developmental outcomes.The workplan proposes a novel 2-step developmental approach: (1) study developmental changes in turn-taking dynamics when children are engaged in open-ended joint play with a parent–measured with motion-capture of participants’ body movements; and (2) and apply these results to extend and test a robotic platform (ARoS) developed at the host institution.In addition, the proposed empirical studies will have far-reaching consequences, beyond human-robot interaction design, in the social, emotional, and cognitive development fields, including clinical applications. The workplan will be supported by a novel interdisciplinary collaboration of a robotics and an experimental psychology laboratory at the host.