stress";: 73 people may have danced to relieve themselves of the stress and poverty of the day,: 72 and in so doing, attempted to become ecstatic and see visions.: 191 another popular theory is that the outbreaks were all staged,: 71 and the appearance of strange behaviour was due to its unfamiliarity.: 137 religious cults may have been acting out well-organised dances, in accordance with ancient greek and roman rituals.: 136 : 137 despite being banned at the time, these rituals could be performed under the guise of uncontrollable dancing mania.: 140 justus hecker, a 19th-century medical writer, described it as a kind of festival, where a practice known as "the kindling of the nodfyr" was carried out. this involved jumping through fire and smoke, in an attempt to ward off disease. bartholomew notes how participants in this ritual would often continue to jump and leap long after the flames had gone.: 139 it is certain that many participants of dancing mania were psychologically disturbed,: 136 but it is also likely that some took part out of fear, or simply wished to copy everyone else.: 43 sources agree that dancing mania was one of the earliest-recorded forms of mass hysteria,: 135 : 73 and describe it as a "psychic epidemic", with numerous explanations that might account for the behaviour of the dancers.: 43 it has been suggested that the outbreaks may have been due to cultural contagion triggered, in times of particular hardship, by deeply rooted popular beliefs in the region regarding angry spirits capable of inflicting a "dancing curse" to punish their victims.