When someone experiences psychosis they are unable to distinguish what is real — there is a loss of contact with reality.

Abstract
Although nearly all domain experts agree that human CO2 emissions are altering the world's climate, segments of the public remain unconvinced by the scientific evidence. Internet blogs have become a vocal platform for climate denial, and bloggers have taken a prominent and influential role in questioning climate science. We report a survey (N > 1100) of climate blog users to identify the variables underlying acceptance and rejection of climate science. Paralleling previous work, we find that endorsement of a laissez-faire conception of free-market economics predicts rejection of climate science (r ~ .80 between latent constructs). Endorsement of the free market also predicted the rejection of other established scientific findings, such as the facts that HIV causes AIDS and that smoking causes lung cancer. We additionally show that endorsement of a cluster of conspiracy theories (e.g., that the CIA killed Martin-Luther King or that NASA faked the moon landing) predicts rejection of climate science as well as the rejection of other scientific findings, above and beyond endorsement of laissez-faire free markets. This provides empirical confirmation of previous suggestions that conspiracist ideation contributes to the rejection of science. Acceptance of science, by contrast, was strongly associated with the perception of a consensus among scientists.

From 9-11, to the death of Osama bin Laden, to the Boston Bombings, there's been a consistently bizarre and troubling reaction by some members of the public.

We're referring to the people—a minority, to be sure, but a surprisingly large one—who always seem to think there's some kind of cover up. The U.S. government, they feel, was really behind the attacks on, uh, itself. And as for Bin Laden—well, he isn't really dead.

These people are called conspiracy theorists, and, their particular form of irrationality is uniquely befuddling. It has been often denounced, but rarely understood. That's too bad, because conspiratorial thinking clearly plays an important role in science denial, on matters ranging from the connection between HIV and AIDS, to the safety of vaccines, to global warming.

Fortunately, conspiracy mongers are now becoming the subject of research and study—and our latest guest is helping to lead this inquiry.

His name is Stephan Lewandowsky, and he's a professor at the school of psychology at the University of Western Australia, and at the University of Bristol in the UK. And he's the author of a recent study with the delicious title "NASA Faked the Moon Landings, Therefore (Climate) Science is a Hoax: An Anatomy of the Motivated Rejection of Science (PDF)"—which drew some small amount of attention, especially when it was followed by a second study of the conspiracy theorists who rejected the first study for, yes, conspiratorial reasons.