Statistical analysis of terrorist groups’ longevity, aims, methods and successes reveal that groups are self-contradictory and self-sabotaging, generally ineffective; common stereotypes like terrorists being poor or ultra-skilled are false. Superficially appealing counter-examples are discussed and rejected. Data on motivations and the dissolution of terrorist groups are brought into play and the surprising conclusion reached: terrorism is a form of socialization or status-seeking.
Terrorism is not about Terror
http://www.gwern.net/Terrorism%20is%20not%20about%20Terror