This report, as part of the "What Is" series on Scientific Frontline provides an extensive, and disturbing examination of the modern phenomenon of conspiracy theories. No longer a fringe curiosity, conspiratorial ideation has evolved into a primary driver of sociopolitical behavior, a mechanism of statecraft, and a significant public health determinant. #Psychology #EvolutionaryBiology #BehavioralScience #SocialScience #sflorghttps://www.sflorg.com/2026/02/wi02172601.html