This paper aims to provide the grounds for a biopsychosocial understanding of the underpinnings of conspiracy theorist ideation by studying research articles from different scientific disciplines. Cross-disciplinary concurring results are presented and discussed, as well as some examples of how conspiracy theories have been used during the 20th century. Also discussed is how this is used in political discourse in the populist climate of today, with the rise of radical right-wing movements, the justification of “alternative facts” from higher governmental ranks, and religious fundamentalism, making it a societal issue of possible big magnitude. Neurological similarities was found between religiousness and proneness to conspiracy theory ideation, and the articles concerning neural correlates therefore stem from research on religious individuals due to the lack of neuro-biopsychological research on actual conspiracy theorists. Since conspiracy theory ideation has shown the ability to cause negative consequences it is also advised that governmental agencies and society as a whole revise its stance on populism and the spread of flawed information, in order to maintain an open society. Also presented are a few ideas on how to begin countering the rise of populism.