There is a widespread idea that societies receiving migratory flows behave with hostility towards theimmigrants. Thus, three arguments underlie the public policies and educational programmes geared to fosteringintercultural values and Active Citizenship competencies in multicultural societies: first, that a strong sense of self-identity is a problem itself in multicultural societies; second, that multiple, hybrids and fluids identities fit better inthe social cohesion principles; and third, that it is possible to train people with formal or non-formal educational programmes with the necessary intercultural values and competencies to live together. However, empirical evidence proves that in Catalonia, Spain, there are indigenous people willing to meet voluntarily with people from differentcultural background. The volunteers for the practice of the Catalan language do this Active Citizenship practicedriven by a strong regional identity and without having had any compulsory or non-formal training in ActiveCitizenship. This research analyses, through the Grounded Theory methodology, this social phenomenon and proposes the conceptual category Responsible trust as the moral value that allows society to strengthen ActiveCitizenship among the adult population that is not of compulsory schooling age.