Steve Mcintyre did some research on Dr Paul Bain – the same who Jo Nova had a long correspondence with a few months ago.

Dehumanizing Language
A few months ago, in an article in Nature Climate Change, Paul Bain, another Australian psychologist, repeatedly used the term “denier” to refer to climate skeptics. Bain defended this usage at Judy Curry’s on the basis that it would “activate the strongest confirming stereotypes” in his target audience:
By using the term “denier” we wanted to start with something that would activate the strongest confirming stereotypes in this audience
Bain’s usage was sharply criticized by skeptic blogs (though it was not an issue that I bothered with.) Judy Curry made the following interesting suggestion:

Somebody needs to research the sociology and psychology of people that insist that anyone that does not accept AGW as a rationale for massive CO2 mitigation efforts is a “denier.”

Judy’s invitation unfortunately was not followed up in the comments. Had this been done, people would have made the surprising discovery that, in his “day job”, Bain primarily wrote about the use and function of derogatory epithets (e.g. cockroach in the Hutu-Tutsi and other racially charged terms). Bain observed that a primary function of dehumanizing language is to reinforce the self-esteem of the “in group”:
For example, Bain observed

Subtle forms of dehumanization are often explained with reference to …the idea that the in group is attributed “the human essence” more than outgroups, and hence outgroups are implicitly seen as “non-human”. ..

People typically evaluate their in-groups more favorably than out-groups and themselves more favorably than others…

such labeling has the effect of denying full humanness to the out group, reinforcing the self-esteem of the in-group..

The denial of full humanness to others, and the cruelty and suffering that accompany it, is an all-too familiar phenomenon…

Despite Bain’s prolific writing on the use and abuse of dehumanizing epithets, he was oddly oblivious to the function of the term “denier” as a means of dehumanizing IPCC critics.

My interpretation of Bains’ scientific research is that likening sceptics to Nazis or pedophiles shows the collective insecurities and feelings of inadequacy of those making the comments. Deep down they know that their beliefs are built on sand, and are desperately finding ways not to acknowledge this. Dehumanizing those who challenge their beliefs is nothing new. It is an easy position to fall into, and takes courage to challenge.