Election 2016 has turned out to be a veritable field day for armchair psychologists—and some professionals, too. This is largely thanks to the unorthodox candidacy of Donald J. Trump. Almost from the moment his campaign rolled out, Trump was tagged in the media as a narcissist, or, even a textbook case of “narcissistic personality disorder.” Others, including Tony Schwartz, co-author/ghostwriter of Trump’s bestselling The Art of the Deal, have described Trump’s fleeting attention span and restless fidgeting (“like a kindergartner who can’t sit still”) in ways that suggest Attention Deficit Hyperactivity Disorder (ADHD). And last week, David Brooks, a conservative columnist for the New York Times, declared that Trump was “psychologically off the chain” with disordered speech patterns that exhibit the “flight of ideas” seen in mania.

Hillary Clinton is not prone to blatant braggadocio or outrageous outbursts, but critics have persistently questioned her utter disregard for State Department rules on email security. Her biggest critics paint her as a “pathological liar.”

Is there anything to such labels? If psychiatrists could directly examine the mental health of the candidates, would any of these diagnoses stick?

And what about another label, one that, if anything, sounds even scarier? To what degree do the modern candidates for President resemble psychopaths

That is the question Oxford University psychologist Kevin Dutton examined for the September/October issue of Scientific American Mind. Dutton, author of The Wisdom of Psychopaths among other books, shows that the eight qualities that define psychopathy in the psychological literature are commonly found in top politicians. And some of them are quite useful.

In his article for Mind, Dutton compared Trump, Clinton and runners-up Ted Cruz and Bernie Sanders to 16 historical leaders in terms of their scores on the short revised form of the Psychopathic Personality Inventory (PPI-R)–a standardized assessment of psychopathic traits. The form was completed on behalf of the candidates by a seasoned political reporter and, for the historical figures, by biographers or other scholars.

The table below reveals each subject’s scores for psychopathy’s eight component traits. The first three traits—social influence (SI), fearlessness (F) and stress immunity (STI), known collectively as the Fearless Dominance traits—tend to be strong in successful leaders. The next four qualities, collectively called Self-Centered Impulsivity, can be more problematic: Machiavellian Egocentricity (ME), Rebellious Nonconformity (RN), Blame Externalization (BE) and Carefree Nonplanfulness (CN). The eighth trait is Coldheartedness (C), which can be helpful in making tough decisions such as sending a nation’s youth to war but is dangerous in excess.

While there is no set score that officially renders someone a psychopath, it’s revealing to see who scores in the top 20 percent of all people who have been evaluated with the PPI-R. The table highlights those with scores in this upper quintile, which are somewhat lower for women than for men.

The verdict on the candidates: Trump, Clinton and Cruz all scored in the upper quintile in Self-Centered Impulsivity and Coldheartedness. Trump landed in the top 20 percent across the board on psychopathy traits, with a total score that placed him between Idi Amin and Adolf Hitler.

To read more of Kevin Dutton’s analysis and to see how all 42 Presidents preceding Barack Obama scored in psychopathy, see the Sept/Oct issue of Scientific American Mind, available on newsstands and on Scientific American.com.

Here is a chart that shows how some of this year's candidates match up with leaders throughout history.