National character (Nationalcharakter, Volkscharakter) as a category of scientific research had been solidly establishing itself in Austrian and Hungarian scientific discussions since the 80s of the 18th century. At the beginning it was the research subject of a complex scientific discipline known as statistics, or politics, (Statistik, Staatskunde). New scientific disciplines were formed during the first half of the 19th century. One of their goals was the examination and description of national character. It had been the subject of the great interest of the state during the Enlighment since the reign of Joseph II. The depictions of national character recorded in statistical data provide a crucial source for the scrutiny of the historical genesis of ethnic, social and denominational stereotypes. The stereotypes were systematically noted down in their established forms. Consequently, the statistical data noticeably contributed to the creation of the fixed meaning and usage of stereotypes known at that time. The authors of the statistics wrote them with patriotical goals and with the aim to improve general knowledge and thus strengthen their native country. During the national character creation layers of new ethnic stereotypes were piled on the older ones. The new stereotypes reacted to social changes, state needs and norms and to interests and expectations of elite. The mutual complementarity of Hungarian and Slovak national characters is evident even at first glance at the statistical data expressing them. Slavic people were due to their number, history and intensity of bilateral contacts, together with Germans, the main referential ethnicity for genuine Hungarians. National character was attractive also for national movement ideologists during the pre-March era since they had realised its mobilization potential. The ideologists attempted to create a tool from national character for reinforcement of the identification with nation and for determining the ideal member of a national collective being formed. Stereotypization, a priori a part of every effort to reduce and divide a heterogeneous social group into certain representative features, was becoming an important instrument of national mobilization.