A comparative framework of inter-individual coordination and pair-bonding

Inter-individual coordination (IIC) at the behavioral and physiological level, and its association with courtship and pair-bond maintenance, have been receiving increased attention in the scientific literature in recent years. However, there is no integrative framework combining the plethora of findings in humans and nonhuman species yet that addresses the evolutionary origins of IIC. Here, we take a comparative approach and review findings on the link between IIC and pair-bond formation, maintenance, and bi-parental care. Our review suggests that across socially monogamous species, IIC – at a behavioral and physiological level – is correlated with the likelihood of forming and retaining a pair-bond, and with reproductive success. We expand on the pair-bonding hypothesis by stating that higher levels of IIC might be beneficial for relationship quality and bi-parental care and, as a result, might also become a preferred trait in the formation and maintenance of a pair-bond. We further discuss the key questions to disentangle the evolution of IIC based on this hypothesis.