Two studies were conducted in West Germany and the United States to investigate cultural similarities and differences on features of personality assessed through act frequency methods. The first study analysed the acts considered to be central and peripheral to each of six dispositional categories: dominance, quarrelsomeness, gregariousness, submissiveness, agreeableness, and aloofness. The results indicated moderate to strong similarity between the cultures in the prototypicality structure for all categories except agreeableness, which showed little concordance. The second study examined the manifested structure of act performance as assessed through retrospective act reports. The results indicated greater similarity of act endorsements between the two sexes within each culture than between cultures within each sex. Generally, the Americans showed higher base rates than the Germans. Furthermore, over all samples, females showed lower base rates than males. The correlations between relative base rates within each of the six different categories were moderately strong between the cultures (0.56, p < 0.001). Analyses of the relations between the prototypicality structure and the manifested structure yielded a complex picture that was highly dependent on dispositional category. For quarrelsome acts, for example, the more central acts were reported to be performed less frequently in both cultures, while other categories showed positive correlations between base rates and prototypicality. The limitations of these studies are described, and future research directions regarding expanding the range of act frequency methods and the number of nations in the search for personality functioning across cultures are suggested.