The topic of risk perception is discussed in relation to data obtained from Japanese students, who appear to have a highly vigilant approach to life's dangers and to welcome warnings, but at the same time have a somewhat fatalistic attitude to their own lives. After an overview of conceptual issues regarding stress and disasters including earthquakes, examples of human responses to massive stress are presented in the cases of an Underground railway fire, an aeroplane hijacking, a ferry boat sinking and a terrorist bomb explosion on a city street. Data are also presented on the coping strategies which people use to attempt to process traumatic events, and therapeutic outcomes from controlled treatment trials.