Research in South Korea and the United States examined how affective states facilitate or inhibit culturally dominant styles of reasoning. According to the affect-as-information hypothesis, affective cues of mood influence judgements by serving as embodied information about the value of accessible inclinations and cognitions. Extending this line of research to culture, we hypothesised that positive affect should promote (and negative affect should inhibit) culturally normative reasoning. The results of two studies of causal reasoning supported this hypothesis. Positive and negative affect functioned like "go" and "stop" signals, respectively, for culturally typical reasoning styles. Thus, in happy (compared to sad) moods, Koreans engaged in more holistic reasoning, whereas Americans engaged in more analytic reasoning.