In August 2016, just a few months before Americans would head to the polls to choose the next President of the United States, a researcher from Oxford University tested then-candidates Donald Trump and Hillary Clinton on psychopathic traits — and found that Trump outscored Adolf Hitler.
Psychologist Dr Kevin Dutton ranked the psychopathic traits of the US presidential hopefuls and historical figures using a standard psychometric tool – the Psychopathic Personality Inventory – Revised (PPI-R).
Mr Trump did not sit the tests himself but experts on political figures gave their opinions on how he would have scored against the questions to measure PPI-R.
The infamous German Nazi scored a total of 169 points, and now-President Donald Trump came in at 171.
Study author Dr Kevin Dutton said: "The PPI-R does not say that someone is or is not a psychopath. It scores them on eight traits that contribute to a psychopathic character.
"Some of those traits, such as fearlessness or stress immunity, can be positive. Others, such as blame externalisation or being unconcerned about the future, are more likely to be negative. One, cold-heartedness, can contribute to good and bad leadership.
"Both great and terrible leaders score higher than the general population for psychopathic traits, but it is the mix of those traits that determines success.
How does Trump’s mix of traits turn out?
Mr Trump outstripped Hitler on factors including social influence and fearlessness, while the Nazi dictator scored higher on Machiavellian egocentricity and cold-heartedness.
Of particular interest, Trump outscored the other candidates in "fearless dominance", the area associated with successful presidencies.
The findings, published in the he journal Scientific American Mind, found that another high-scoring area for the billionaire businessman, self-centred impulsivity could undermine this, however.