Joint action with human versus robot partners across psychological domains: a systematic review

When they act together, people engage a myriad of cognitive and social processes which are increasingly investigated in various areas of psychological and neuroscientific research. The study of human-robot joint action holds promises not only in terms of applying findings to robotics but also providing innovative methodologies that can help disentangle the determinants of human-human joint action. But, how does acting jointly with a robot compare to co-acting with a human? Research investigating this question is sparse and an overview of relevant findings is missing. Therefore, this paper provides a systematic review of the studies assessing differences and similarities between behavioral, neural, and/or subjective dimensions of human-human and human-robot joint action. After examining general trends in this research area, we analyze findings from 39 included studies in domains ranging from continuous and discrete action coordination, to verbal and non-verbal communication, to decision-making, sense of agency, and attitudes toward the partner. The quantitative or qualitative comparisons made in these articles show heterogeneity in terms of both findings and methodologies. In most domains, results regarding potential differences between human-human and human-robot conditions are nuanced. In conclusion, we highlight a few open questions and challenges for this research area and emphasize how examining human-robot joint action is valuable both in case of differences and similarities with its human-human counterpart.