From journal abstract:
Why do groups adopt terrorism? Major theories of terrorist radicalization assume it to be a rational process whereby groups select terrorism as the policy most likely to advance their goals. Not all terrorism is rational, however, and these theories cannot explain cases when groups pursue terrorism despite it being self-defeating. We distinguish between rational and irrational terrorism, and explain the latter using social psychology's groupthink mechanism. Although terrorists are widely assumed to be vulnerable to groupthink, empirical work on the phenomenon has focused overwhelmingly on decision-making by national executives. We firmly establish the link between groupthink and terrorist radicalization by tracing groupthink's operation through the development of the Weather Underground, an American terrorist group that emerged in the late 1960s and conducted six years of bombings against the U.S. government. All of the antecedent conditions, symptoms, and decision-making defects predicted by groupthink are evident in the Weather Underground, providing valuable evidence of the dangers of irrational radicalization and offering lessons for its prevention.