Trust Emerges From Shared Attention: Behavioural and Neural Evidence From Dual EEG Hyperscanning.

Trust is central to human cooperation, yet the cognitive and neural mechanisms through which it emerges remain poorly understood. Here, we tested whether shared attention fosters trust behaviour and its neural underpinnings. Pairs of participants engaged in a joint flanker task to manipulate attentional alignment, followed by a multi-round trust game, whereas neural activity was recorded using dual EEG hyperscanning. Behaviourally, participants in the shared attention condition invested more and responded faster than those in the separated condition, with effects evident from the first round and persisting across repetitions. Neurally, shared attention was associated with increased prefrontal oscillatory power in the theta, alpha, and beta bands, stronger beta-band functional connectivity between prefrontal and posterior regions, and enhanced inter-brain theta synchronisation in right frontal areas. Together, these findings demonstrate that shared attention promotes trust through a multi-level mechanism spanning local oscillatory activity, intra-brain connectivity, and cross-brain coupling, establishing shared attention as a minimal yet robust pathway for trust formation beyond deliberative or experience-based accounts.