(May 11, 2016, 1:34 PM EDT) -- PHOENIX — A social psychologist may opine in a tax-evasion lawsuit that certain people exhibit a general conspiracy mentality that makes them susceptible to belief in a wide variety of conspiracy theories, an Arizona federal judge ruled May 10; however, the judge barred the expert from testifying that a defendant’s beliefs are sincerely held (United States of America v. Gary Steven Christensen, No. 14-08164, D. Ariz.; 2016 U.S. Dist. LEXIS 61673)....