Can social identity theory address the measurement tangle in survey-based national identity research?

Survey-based research on national identity has long grappled with a ‘tangle’ of conflicting concepts, inconsistent use of measures and inconclusive empirical findings. This article addresses the measurement side of this tangle, evaluating whether social identity theory (SIT) can serve as a conceptual framework to clarify and organize existing indicators. Drawing on methods from content validity analysis, we examine survey instruments from the National Identity module of the International Social Survey Program (ISSP). The analysis shows that all items can be related to SIT's central components, including identification and content dimensions. However, many items cannot be unequivocally assigned to a single concept within SIT, and the degree of ambiguity varies across items. These findings highlight both the promises and the limitations of SIT as a structuring tool for addressing empirical challenges in national identity research and point to the need for further theoretical and methodological refinement in this field.