Consumers around the world often give voluntary sums of money (called “tips”) to the service workers who have served them, but the set of tipped professions and the amounts tipped to any one profession differ from country to country. One explanation for these national differences in tipping customs is that they reflect national differences in attitude toward tipping, sensitivity to duty/obligation to tip, and sensitivity to social pressure to tip. Furthermore, these variables have been hypothesized to mediate the previously observed effects on tipping customs of national extraversion, psychoticism and neuroticism respectively. Analyses of secondary data found support for these explanations of national differences in tipping customs, but only partial support for their roles as mediators of national personality effects on tipping customs. The theoretical and practical implications of the findings are discussed along with study limitations and directions for future research.