Neural synchrony is not unique to romantic bonds
Year: 2026
Type: preprint
Study design: Observational Study
Abstract: Prior research suggests that romantic couples exhibit heightened inter-brain neural synchrony (INS) compared with other close relationships. However, because couples typically spend more time together and share living environments, elevated INS may reflect social proximity and accumulated shared experience rather than romantic attachment. The present study tested these theories by comparing romantic couples with roommates who share sustained cohabitation and interaction but lack a romantic bond. Electroencephalography (EEG) was recorded from 72 participants (20 couples, 16 roommate pairs) while they viewed positive, negative, and neutral emotionally evocative films. INS was quantified using the Phase Lag Index (PLI) across four frequency bands and 12 regions of interest (ROIs). PLI did not differ between couples and roommates across any frequency band, ROI, or emotional condition, and relationship satisfaction was not associated with PLI. Greater emotional similarity was associated with higher beta-band PLI among roommates during negative emotional processing. Longer relationship duration was associated with higher theta-band PLI in both groups, although in different ROIs and emotional conditions. These findings suggest that neural synchrony may reflect accumulated shared experience rather than relationship category, reframing INS as a consequence of two brains repeatedly inhabiting the same world.
Source: PsyArXiv (OSF Preprints)
Language: English
Subfield: Social Psychology
Field: Psychology
Domain: Social Sciences
Open Access status: green
OpenAlex ID: W7213518114