Resource Unpredictability, Mistrust, and War

Abstract
The results of this cross-cultural study suggest that war may be caused mostly by a fear of nature and a partially resultant fear of others. A history of unpredictable natural disasters strongly predicts more war, as does socialization for mistrust (but less strongly). It seems that people, particularly in nonstate societies, may try to protect themselves against future disasters by going to war to take resources from enemies.