This article reports a test of the hypothesis that national differences in personality traits are expressed by national differences in how accurately the final letter of the personal name designates the female or male gender. The names were obtained from lists of more than 80 popular names in each nation, separately for females and males. Gender designation was more accurate for female than male names. In nations with more accurate gender designation of the final letter of first names, four personality traits self-reported more often by inhabitants are high uncertainty avoidance, high power distance (PD), low individualism (Ind), thereby high collectivism, and a low proportion who are very happy (VH).