Cardiac synchrony during collaborative drawing: A longitudinal comparison of same generation and intergenerational dyads

Intergenerational social programs provide opportunities for people of all ages to form new relationships. Furthermore, existing qualitative and behavioural evidence from such programs points to health and wellbeing benefits, yet the physiological consequences of repeated intergenerational encounters remain unknown. A deeper understanding of how such programs shape dyadic physiological responses will illuminate the mechanisms of relationship formation. Across a six-session collaborative drawing program, we tracked cardiac synchrony within 31 intergenerational (older/younger adult) and 30 same generation (younger adult) dyads. Each session dyads completed self-report measures, then drew together and alone, while we recorded participants actions with motion capture and physiological signals (neural and cardiac) using fNIRS. Collaborative behaviour, self-reported social closeness, and interpersonal distance (i.e., proximity) showed group-specific patterns, whereby interpersonal distance emerged as a promising objective measure of relationship development. Cardiac synchrony did not covary with group, task, an interaction thereof or any measure of behaviour or social closeness-yet there was a trending relationship between collaboration while drawing together and cardiac synchrony for intergenerational dyads only. In summary, cardiac synchrony pointed to marginally enhanced arousal during active collaboration between older and younger adults. Relationship development was better characterised, in this study, by behaviour and self-report measures than cardiac synchrony.