A character trait in psychopaths has been identified by scientists as a common thread in successful US presidents.
科学家发现，成功的美国总统都具有某种共同的心理病态性格。
Fearless dominance, which is linked to less social and physical apprehensiveness（领悟力）, boosts leadership, persuasiveness, crisis management and congressional relations, according to new research.
Theodore Roosevelt, regarded as one of the most influential US leaders even though he was in office more than a hundred years ago, ranked highest for this type of personality followed by John F Kennedy, Franklin D Roosevelt and Ronald Reagan.
Then came Rutherford Hayes, Zachary Taylor, Bill Clinton, Martin Van Buren, Andrew Jackson and George W Bush.
Fearless and dominant people are often a paradoxical（矛盾的） mix of charm and nastiness. Cool and calm under pressure, they not easily rattled.
They lack the same kind of anticipatory（预期的） anxiety that most people have so are not put off from taking dangerous actions.
They are usually intelligent and wealthy, relishing directing other people's activities and basking in their admiration.
The analysis, published in the Journal of Personality and Social Psychology, drew upon personality assessments of 42 presidents up to George W Bush and compiled by Steven Rubenzer and Thomas Faschingbauer for their book 'Personality, Character and Leadership in the White House.'
More than a hundred experts including biographers, journalists and scholars who are established authorities on one or more US presidents evaluated their target presidents using standardised psychological measures of personality, intelligence and behaviour.
For rankings on various aspects of job performance, the analysis relied primarily on data from two large surveys of presidential historians.
The rich historical data on presidents, combined with detailed expert rankings, provided a window into an emerging theory some aspects of psychopathy may actually be positive adaptations in certain social situations.
