The article reports results of representative survey studies in border regions of Germany, Poland, the Czech Republic, and France. It addresses the proposition that border regions are laboratories of social integration in Europe, and tests to what degree the endowment with transnational social capital (TSC) predicts individual transnational identities with regard to the immediate border region and to Europe as a whole. Results show that only in the border region of Germany and France is there a relationship between accumulated TSC and strength of transnational identity, whereas in the border regions of Germany, Poland, and the Czech Republic, the accumulated individual TSC does not predict transnational identities, which are there more an outflow of political attitudes and reflections about historic conflicts.