This chapter discusses how conspiracy theories disseminated as part of fake news take hold by simultaneously appearing scientific and being unfalsifiable. The evidence reviewed here explains that conspiratorial arguments and related misinformation appear plausible and unfalsifiable because people have high needs of knowledge, ego defense, and social integration. All in all, however, the effects of chronic motives are only moderate in size and fail to explain the social influence processes underlying conspiracy theories and fake news. Future research directions are discussed, particularly the need to analyze the effects of media and group norms in the context of emerging technologies.