This study examines the causes behind the linguistic changes in the field of social vulnerability that in a Western European context has occurred the past three decades. The background of the study is the development where concepts as poverty, marginalization and underclass has declined in use while politicians and scientists today rather speaks in terms of social exclusion, advanced marginality and the Swedish term “utanförskap”. The research aim is justified by the fact that these concepts are used in social policy and thus has direct consequences for those described. The study resulted in three explanatory models on why the language around social vulnerability has changed; (1) Structural changes in society are creating new forms of social vulnerability, (2) New social theories and traditions of thought creates new perspectives on social vulnerability and (3) New concepts introduced by political intentions. Changes in material conditions and structures in combination with new social theories, in the transition between a modern and a postmodern perspective, created new concepts that came to be represented by politicians in Western Europe and North America. The meaning of the concepts has changed from describing people included in society, the majority of poor workers, to describing excluded minorities, excised from their civil rights. The linguistic changes has also meant a shift from one-dimensional to multidimensional terms, from a vertically illustrated the vulnerability to a horizontal one and to a greater focus on the process of vulnerability.