Most of these clusters corresponded closely to the analysed contexts: 2 food-sharing clusters, 2 grooming clusters, 2 joint-travel clusters, 1 nursing/joint ventral travel cluster. However, one cluster was an exception containing “attention-getting” signals like whimper and exaggerated loud scratch.

Almost all adjacency pairs were ‘directional’, meaning they occurred either from mother to infant, or from infant to mother. This indicates an interactional asymmetry that is similar to human caregivers and infants, where both partners contribute differently depending on their goals or needs

To find out, we analysed 361 interactions between mother and infant Ngogo chimpanzees. We recorded 3647 signals and actions across four contexts (food sharing, grooming, nursing, and joint travel) and analysed two fundamental aspects of sequence organisation: adjacency pairs, and flexibility.