Many people take safety measures in order to be prepared in the case of an emergency, such as storing bottled water, canned food, flashlights, batteries and whatnot. Survivalists, however, go one, or rather, many steps farther by basing their entire lifestyle on an ongoing preparation for major social and political disruptions. Some of the events that survivalists fear, or even expect, will happen are clusters of natural and/or nuclear disasters; war; collapse of society due to shortage or unavailability of electricity, fuel, food, water; economic collapse, a sudden pandemic; and basically any other panorama of the end times.
Survivalism is believed to have originated in the 1960's, when the threat of a nuclear conflict between the United States and Russia was latent, and even though the movement has gone somewhat dormant, events in every decade have brought new waves of survivalism, for instance the 1973 crisis, the renewed US-USSR arm race in the 80's, the Y2K computer bug in 1999, and the 9/11 events.
Categories of survivalists, which may overlap each other, include safety preparedness oriented (learns principles and techniques for surviving such common calamities as structure fires, dog attacks, physical confrontations, snake bites, lightning strikes, car breakdowns, bear encounters, flash floods, home invasions, train wrecks and others that can occur anywhere at any time), wilderness survival emphasis (is concerned with thirst, hunger, climate, terrain, health, stress and fear in cases of plane crashes, shipwrecks, being lost in the woods), self defense driven (personal protection, martial arts, self defense tactics), brief natural disasters (tornado, hurricane, flood, wildfire, earthquake or heavy snowfall), long natural disasters (unusually long and cold or warm periods), indefinite natural disaster (global warning or cooling), bio chem scenario (spread of diseases through biological agents), malthusian (uncontrolled human population growth), monetary disasters investors (preparing for paper money to become worthless through hyperinflation), and others.