In a recent special on the History Channel, Bob Woodward asked Dick Cheney to state the most important personal quality of a successful president (Time Magazine and "Frontline" have posed similar questions to others from previous administrations). In a decade-long, scientific assessment of all the presidents we found that psychologically, Teddy Roosevelt epitomizes the qualities of a successful president. Not Washington or Jefferson, not Lincoln or FDR, but Teddy, with his flashing teeth, his over-use of expletives, and his embarrassing foreign policy filled the bill better than anyone to date.

We asked 120 noted biographers and others who knew one or more presidents well (e.g., John Ehrlichman) to evaluate each chief executive using a 592-item battery of personality tests. We found nine personality traits that distinguished presidents as rated great by historians. Not all of these traits are positive; we found the tendency to lie and deceive to be associated with the more successful chief executives. Although this may grate on moral sensitivities, FDR and Jimmy Carter provide two ready examples of why deceit and dissembling (FDR) may be of great value, while honesty and straightforwardness (Carter) may cause irreparable harm. The other traits, in approximate order of their importance, are Assertiveness, Tender-Mindedness, Achievement Striving, Intellectual Breadth and Depth, Activity Level, Positive Emotions, Competence, and the ability to function under stress (Low Vulnerability). Teddy Roosevelt had most of these in spades, although he was only about average among presidents in his concern for the less fortunate (Tender-Mindedness).

We also tested whether “character” was at all related to presidential success. Studies in the workplace consistently find integrity tests to predict performance on the job, especially bad behaviors such as theft and absenteeism. Nonetheless, no matter how we defined it, character had little correlation with historian polls of presidential success. But lack of character did predict ethical problems in office, as we might expect from findings in the private sector. This was true for personalities as disparate as Warren Harding, Richard Nixon, and Bill Clinton.

Because we used a standardized test that has been administered to a large number of typical Americans, we were able for the first time to compare the personalities of presidents to the people they represent. Presidents, as a group, have been more Assertive, Achievement-Striving, traditional in values, and less Straightforward than average Americans. In other words, they have been dominant, ambitious, conservative, but somewhat devious men. We found that current presidents tend to be very extraverted (about 90th percentile), while early presidents tended to be more introverted than most present-day Americans. The Founders also were more philosophical (consider Adams, Jefferson and Madison vs. LBJ, Reagan, and the Bushes) and rated higher on some measures of character than the current office holders. Recent Democrats and Republicans (up through G. H. W. Bush) differ in terms of personality as well as policy: Democrats (FDR through Clinton) were rated as ambitious, energetic, devious, undependable, and tenderhearted by their biographers, whereas Republicans were generally considered very conservative in values, unsympathetic toward the disadvantaged, and uninterested in philosophy or intellectual play. Other than Nixon, however, they scored much higher than Democrats on indices of character.

We also explored whether there are discernable presidential personality types by examining how similar the presidents’ personalities are to each other, using experts’ ratings on all 592 items of our questionnaire. We found eight types of presidents: Dominators (LBJ, Nixon, A. Johnson, Jackson, Polk, T. Roosevelt, and Arthur), Introverts (J. Adams, J. Q. Adams, Nixon, Hoover, Coolidge, Buchanan, Wilson, and B. Harrison), Good Guys (Hayes, Taylor, Eisenhower, Tyler, Fillmore, Cleveland, Ford, and Washington), Innocents (Taft, Harding, and Grant), Actors (Reagan, Harding, Harrison, Clinton, and Pierce), Maintainers (McKinley, G.H.W. Bush, Ford, and Truman), Philosophes (Garfield, Lincoln, Jefferson, Madison, Carter, and Hayes), and Extraverts (FDR, Kennedy, Clinton, T. Roosevelt, Reagan, W. Harrison, Harding, Jackson, and LBJ). Although our major purpose was to identify types of presidents based on personality, it turns out that some types tend to make better presidents than others: Philosophes and Extraverts tend to perform better than average, while Introverts and especially Innocents perform below average.

Of course, every person is unique. Even highly similar presidents, such as Clinton and JFK, still had important personality differences. One major goal of our project was to provide objective, highly detailed personality portraits of the individual presidents. To do this, we analyzed experts’ responses to each of the 592 items, selecting those that were most strongly and consistently endorsed by our experts, and occasionally added a pertinent anecdote for illustration. For example, Theodore Roosevelt rated very high on the item “He uses words like ‘fantastic’ or ‘sensational’ to describe his personal experiences.” Paraphrased, this description begins our personality portrait of Roosevelt, followed by descriptions (items) that were also rated highly:

T. R. used superlatives, such as his trademark “That was bully!,” a great deal more than most presidents. He often would literally "jump for joy” and was known to celebrate victories by whooping and dancing. Strong emotions clearly gave his life meaning, and he was not always able to keep them under control. He was uncommonly carefree, happy-go-lucky, and spontaneous, and clearly showed his emotions. He experienced periods of intense joy and laughed easily.

We produced similar profiles for all of the prominent past presidents, and preliminary ones for G .W. Bush and John Kerry. Bush is interesting because he scores well below the average president on many of our presidential success factors, with low scores on Competence (keeps well-informed, makes good decisions), Achievement Striving (works hard to meet goals), and Tender Mindedness. He scored highly only on Positive Emotions (enthusiasm and humor), but also most resembled two successful presidents. Bush’s similarity to Reagan (much more than to his own father) has been noted. However, we found Bush to most resemble another charismatic, combative, incurious extravert -- Andrew Jackson.

Like Jackson, Bush has appeared indifferent to science and has been accused of subverting scientific inquiry and attempting to bend empirical findings to meet his political agenda. Jackson, the old Indian fighter, did not forget a grudge nor seek compromise with his opponents, either in his personal life or in government. Will Jackson’s policy towards Native Americans play out in Bush’s war on terrorism? Many things other than personality affect a person’s behavior, even for strong-willed presidents like Old Hickory and W. Although Bush and Jackson are similar, they are hardly identical— Jackson seems to have been higher in Achievement-Striving before becoming president, while Bush was higher on Positive Emotions.

Lastly, we were able to compare Bush and his opponent in the 2004 election in terms of their personal suitability for the job, aside from their politics and policies. Kerry was higher than Bush on four factors (Competence, Achievement-Striving, Intellectual Breadth and Depth, and Tender-Mindedness) related to presidential success. Bush was clearly higher on Positive Emotions. Both candidates also scored low (10th percentile or lower) on both Character and Agreeableness. Polls suggested that voters perceived Bush to be the stronger leader, probably because of his moral clarity, steadfastness, and ability to communicate simply and effectively. Yet, our analysis suggests that Kerry had more of the personal assets that make for a good president.