Cultists are the most extreme liars.
From WAPO: Dec 8 2017
Bella DePaulo
Bella DePaulo, a social scientist, is the author of "Singled Out: How Singles Are Stereotyped, Stigmatized and Ignored" and "How We Live Now: Redefining Home and Family in the 21st Century."
I spent the first two decades of my career as a social scientist studying liars and their lies. I thought I had developed a sense of what to expect from them. Then along came President Trump. His lies are both more frequent and more malicious than ordinary people's.
In research beginning in the mid-1990s, when I was a professor at the University of Virginia, my colleagues and I asked 77 college students and 70 people from the nearby community to keep diaries of all the lies they told every day for a week. They handed them in to us with no names attached. We calculated participants' rates of lying and categorized each lie as either self-serving (told to advantage the liar or protect the liar from embarrassment, blame or other undesired outcomes) or kind (told to advantage, flatter or protect someone else).
https://www.washingtonpost.com/outlook/i-study-liars-ive-never-seen-one-like-president-trump/2017/12/07/4e529efe-da3f-11e7-a841-2066faf731ef_story.html