National innovativeness is one key driver of economic development. The relation of national innovativeness and national culture has been firmly established by research. Cultural factors, however, influence national innovativeness via different mechanisms on the macro-, meso-, and micro-level of a country. In our article, we build on existing research on the link between cultural dimensions and national innovativeness to develop a new model that classifies different cultural dimensions in groups according to their mechanism: political, social, or individual (PSI-model). Using a newly established data set composed of world data, we test and find support for this model using a variety of regression models. The PSI-model provides a more structured theoretical background of the impact of different cultural dimensions on national innovativeness, especially with regard to social practices and social values. It can be used to generate policy recommendations on national innovativeness and offers further applications in fields related to the various impacts of national culture.