Background This paper advances the theory of “cultural signatures” in personal networks by integrating Goodenough’s concept of propriospect—the individual’s internalized model of culture—with a personal network approach to social structure. We define cultural signatures as the structural traces left by cultural institutions—such as kinship systems, gender regimes, religious practices, and educational norms—in personal networks. To illustrate this theoretical framework, we revisit Fredrik Barth’s ethnography of Sohar, an Omani town characterized by multiculturality and gender segregation. Using the propriospect approach, we show how shared cultural codes of politeness and self-restraint sustain social diversity and how institutions (market, mosques, Wali court, and neighborhoods) shape the gendered topology of personal networks. Methods Drawing on a web survey in six countries selected across Gelfand’s tight–loose cultural range, we collected 1,815 personal networks, about 300 by country, with egos nominating 30 alters and the alter-alter ties. Along with this rich structural information, we collected sociodemographic variables and moral values. The data was analyzed using forest tree methods to predict the country of origin from structural, sociodemographic, or moral values variables. Results We demonstrate that network structures significantly contribute to predicting respondents’ cultural background (country of origin in this case), supporting the hypothesis that social interaction patterns encode identifiable cultural imprints. Conclusions By linking cognitive models of culture with measurable meso-level social structures, the paper provides a conceptual and methodological framework for analyzing how cultural diversity manifests in patterns of social interaction.