Abstract
Ethnolinguistic vitality (ELV) studies have long explored the functioning of minority communities, emphasizing the role of language and collective identity as key unifying factors. Since 2021, an ELV study in Poland has focused on collateral language communities – autochthonous groups linked to specific territories, whose languages are closely related to the dominant national language and often misclassified as dialects. These communities are typically unrecognized, and their group distinctiveness is frequently questioned. To assess their internal cohesion, a latent variable – Collective Identity – was developed within the ELV framework. This allows for evaluating whether such communities, often viewed as regional rather than ethnic groups, exhibit shared features and a sense of collective belonging. The findings indicate that collateral language communities form distinctive entities, characterized by shared language and cultural values, thus challenging assumptions about their peripheral or non-ethnic status.