"Certain psychopathic traits may be like a double-edged sword," lead author Scott Lilienfeld, a psychologist at Emory University in Atlanta, said in a statement. "Fearless dominance, for example, may contribute to reckless criminality and violence, or to skillful leadership in the face of a crisis."
Lilienfeld and colleagues analyzed personality assessments of 42 presidents, up to George W. Bush, compiled by Steven Rubenzer and Thomas Faschingbauer for their book "Personality, Character and Leadership in the White House."
The authors drew on more than 100 experts, including biographers, journalists and scholars who are established authorities on one or more U.S. presidents, evaluated their target presidents using standardized psychological measures of personality, intelligence and behavior.
Rankings on various aspects of job performance came from two large surveys of presidential historians: One conducted by C-SPAN in 2009 and a second by Siena College in 2010.
The study, published in the Journal of Personality and Social Psychology, found Theodore Roosevelt ranked highest in fearless dominance, followed by John F. Kennedy, Franklin D. Roosevelt, Ronald Reagan, Rutherford Hayes, Zachary Taylor, Bill Clinton, Martin Van Buren, Andrew Jackson and George W. Bush.
A clinical psychopath encompasses many characteristics, such as fearless social dominance, self-centered impulsivity, superficial charm, guiltlessness, callousness, dishonesty and immunity to anxiety and all people exhibit one of more of these traits to some degree, Lilienfeld said.
The link between fearless dominance and political performance was linear, but at the extreme, boldness might veer into a form of recklessness, Lilienfeld said.