What is "denialism"

n. The practice of rejecting propositions which are strongly supported by scientific or historical evidence, and often of seeking to influence policy processes and outcomes accordingly.

In the psychology of human behavior, denialism is a person's choice to deny reality, as a way to avoid a psychologically uncomfortable truth. Denialism is an essentially irrational action that withholds the validation of an historical experience or event, by the person refusing to accept an empirically verifiable reality. In the sciences, denialism is the rejection of basic facts and concepts that are undisputed, well-supported parts of the scientific consensus on a subject, in favor of radical and controversial ideas. The terms Holocaust denialism and AIDS denialism describe the denial of the facts and the reality of the subject matters, and the term climate change denialist is applied to people who argue against the scientific consensus that the global warming of planet Earth is a real and occurring event primarily caused by human activity. The forms of denialism present the common feature of the person rejecting overwhelming evidence and the generation of political controversy with attempts to deny the existence of consensus. The motivations and causes of denialism include religion and self-interest (economic, political, financial) and defence mechanisms meant to protect the psyche of the denialist against mentally disturbing facts and ideas.