This study was an attempt to determine whether the degree of laughing in a variety of situations is related to Extraversion. In order to measure smiling and laughing, the Situational Humor Response Questionnaire (SHRQ) (Martin and Lefcourt, 1984) was given to 165 German university students and non-students and to 118 American university students. Extraversion and also Psychoticism, Neuroticism, and Social Desirability were measured by the revised Eysenck Personality Questionnaire (EPQ-R; Eysenck, Eysenck and Barrett, 1985). SHRQ scores correlated 0.52 and 0.36 with Extraversion, 0.26 and 0.26 with Psychoticism, and negligibly with Neuroticism in the German and American samples, respectively. The positive correlations between Extraversion and laughing propensity were interpreted as confirming the hypothesis that the 'tendency to laugh' is a characteristic of extraverts. This tendency generalizes across situations and is not just limited to humorous ones. The SHRQ items correlating significantly with Psychoticism were interpreted as reflecting different evaluations of these particular situations by high and low P scorers rather than as determining a general tendency to laugh.