Inter-brain synchrony is associated with greater shared identity within naturalistic conversational pairs

Br J Psychol. 2025 Feb;116(1):170-182. doi: 10.1111/bjop.12743. Epub 2024 Oct 26.

Abstract

Inter-brain synchrony occurs between individuals who feel connected socially, but how synchrony relates to felt connectedness under naturalistic social interaction has remained enigmatic. We hypothesized that inter-brain synchrony between naturally interacting individuals might be associated with the internalization of a social identity, a link between an individual's personal identity and the social group to which the individual belongs. A convenience sample of sixty participants were split into dyads and interacted naturalistically on a social task. Through mapping EEG oscillatory waveforms onto a conceptual model categorizing the formation of a social identity within a naturalistic conversation, greater inter-brain synchrony was observed in the emergent stage within the formation of a social identity compared to earlier stages, where a social identity was not present. We provide evidence for greater neural synchrony related to higher socio-psychological connectedness during the development of social identity under naturalistic social interaction.

Keywords: EEG; connectedness; inter‐brain synchrony; natural social interaction; neural synchrony; social behaviour; social identity.

MeSH terms

  • Adolescent
  • Adult
  • Brain* / physiology
  • Electroencephalography*
  • Female
  • Humans
  • Interpersonal Relations
  • Male
  • Social Identification*
  • Social Interaction*
  • Young Adult