In addition to ideological entanglements that go beyond its inherent mandate, survivalism itself can lead to dangerous behavior. Most obviously, in the context of the Lanza family, someone who believes the government is on the verge of collapse might stockpile weapons and train his or her children how to use them effectively without taking a full inventory of that child's mental fitness.
While there's not much solid research to be had, anecdotal observations certainly give the impression that there's a higher incidence of mental illness among hardcore preppers than in the general population, and the nature of their beliefs and social networks may create obstacles to diagnosis and treatment. There can be fine lines between reasonable fear, intense fear, and irrational fear, and some preppers subscribe to conspiracy theories that are completely nuts, focused on supposed threats from sinister "chemtrails" to the Illuminati (or both and then some).
For all these reasons, there have been a number of cases where survivalism and violent actions were fellow travelers, aside from the well-documented case of McVeigh. The 1995 Olympic Park bomber, Eric Rudolph, was a survivalist, in addition to being an anti-abortion extremist. In 2004, police broke up an illegal weapons ring centered around several militia and survival groups. And in April of this year, Washington state survivalist Peter Keller killed his wife and daughter and then locked himself into a fortified rural bunker, where he killed himself after a standoff with police.
But a video Keller recorded before his death suggested his actions were not connected with his survivalist beliefs so much as his inability to survive ordinary life. Although his preparations created obvious complications for police trying to apprehend him, his beliefs did not seem to play a role in his murderous acts.
Therein lies the rub. A search of news archives yields hundreds of cases over the last 20 years of less prominent murderers and felons who were said to be survivalists, but the term is often bandied about loosely by police and reporters groping for a simple explanation of inaccessible motives or the possession of sophisticated weaponry.
The extremity of Adam Lanza's crime has created a desperate desire for explanations, and dismissing him as a crazy survivalist -- or the son of a crazy survivalist -- will likely prove irresistible for many people trying to make sense of a senseless act. But the ultimate truth of his motive is not likely to be so simplistic. Survivalism does not justify slaughtering children, although fear of an impending and unbearable apocalypse might move a twisted mind toward such an act.
Additional information will emerge over the coming days, but we may never really know why Lanza killed his mother and so many innocent teachers and children. Understanding the context of his actions may provide useful insights that could prevent future incidents, but gross oversimplifications will only stand in the way.