Misleading Headline: These are "Traits," not "Reasons"
Traits might mean that a person has a tendency to accept conspiracy as a viable theory.
Others may have traits that make it difficult for them to see conspiracy even when it does exist (Gulf of Tonkin, Nazi Death Camps, etc.)
History has plenty of examples of both.
"Reasons" would be factual matter (for which conspiracy may or may not be a viable explanation:)
A 1000-page report that neglects the fact that a 47-story building that fell down -- I mean, neglects to mention that it happened, let alone offers an explanation.
A claim that, even though the attack was a complete surprise, teams were dispatched to collect every video with a view of the Pentagon strike within an hour.
Facts that don't seem to fit the explanations offered: those are the reasons people suspect conspiracy.
Shermer claimed that certain traits make conspiracy a more or less acceptable theory. If there were no perceived discrepancies in the available data, personality traits would be a null issue. Please be more careful.