Students in my classes confirmed the social nature of laughter by recording the circumstances of their laughter in diaries. After excluding the vicarious social effects of media (television, radio, books, etc.), its social nature was striking: Laughter was 30 times more frequent in social than solitary situations. The students were much more likely to talk to themselves or even smile when alone than to laugh. However happy we may feel, laughter is a signal we send to others and it virtually disappears when we lack an audience.