He had a very high energy level. Said Gunther: “His vitality was, as everybody knows, practically unlimited. In one campaign he traveled 13,000 miles in about 7 weeks, and made 16 major and 67 second-string speeches — not to mention innumerable back platform appearances and never stopped having a wonderful time.”

In the 12 years of his presidency, he made 399 trips by rail, covering about 545,000 miles. In 1936, the strenuous campaign exhausted the physically healthy Republican candidate, Alf Landon; doctors advised him to take to bed in its final days. The paralyzed president, in contrast, showed no strain. Thinking also of F.D.R.’s distant cousin, the exuberant Theodore Roosevelt, the journalist (and F.D.R. critic) H. L. Mencken reflected, “The Roosevelt family is completely superhuman. No member of it ever becomes tired.”

He was extremely extroverted and sociable. He spent about a quarter of the working day on the telephone. A circle of about 100 advisers knew they could call him at any time on the telephone without means of an intermediary. He knew how to get people to do what he needed, even if they did not agree with him about why. “You know, a man will do a lot of right things for the wrong reasons,” he once explained when asked why he sought opponents to serve in his administration.

His thinking was manic: expansive, creative, divergent. His labor secretary and friend, Frances Perkins, noted that F.D.R. was not a “careful, direct-line administrator”; rather his method of “not giving direct and specific orders to his subordinates released the creative energy of many men ... His four-track mind proved invaluable ... he could keep many activities operating at top efficiency.” Roosevelt was a whirlwind of a leader, an entrepreneurial president, always thinking ahead. After the first wave of New Deal laws, Vice President John Nance Garner advised the impatient leader, “Mr. President, you know you’ve got to let the cattle graze.” F.D.R. once even wrote a memorandum addressed to whomever would be president in 1956.

A key aspect to hyperthymic personality is the trait of “openness to experience.” People with hyperthymic personality are curious, inventive, experimental souls. Roosevelt’s intellectual openness was evident in his invention of the concept of a “brain trust” during the 1932 campaign, a reliance on academic expertise that has since become common but at the time was quite unusual. Roosevelt always sought a wide range of ideas. He once said, “You sometimes find something pretty good in the lunatic fringe. In fact, we have got as part of our social and economic government today a whole lot of things which in my boyhood were considered lunatic fringe, and yet they are now part of everyday life.”

But hyperthymia by itself does not ensure greatness; one also needs to be tested by adversity, and emerge stronger. Before suffering polio at age 39, F.D.R. was a successful patrician: secretary of the Navy in Woodrow Wilson’s administration, vice presidential candidate in 1920. Then, suddenly, for about a decade, he had to put all his immense energies into the mere effort to walk. He could have been destroyed by his paralysis; instead, he was transformed. The magic of hyperthymia made him recover from his illness stronger, not physically but psychologically. Said Perkins: “Roosevelt underwent a spiritual transformation during the years of his illness. I noticed when he came back that the years of pain and suffering had purged the slightly arrogant attitude he had displayed on occasion before he was stricken. The man emerged completely warmhearted, with humility of spirit and with a deeper philosophy.”

The cocktail for Roosevelt’s political resilience was his hyperthymic personality, along with the adversity of medical illness. His hyperthymic personality made him open to new ideas, and charismatic, but also, in the face of polio, hyperthymia helped him to be resilient, to rise above and better understand human suffering. This psychological evolution may have helped him handle the huge crises of economic depression and world war. His mind was agile and he did not recoil from the most terrible of decisions. His attitude was, Perkins said, that “nothing in human judgment is final. One may courageously take the step that seems right today because it can be modified tomorrow if it does not work well.” She thought this attitude freed Roosevelt to act. Indeed it did. But this pragmatism was psychological, not theoretical, for F.D.R.; it was part of his hyperthymic temperament, the always active mind that would never have given him the option of standing still. F.D.R.’s hyperthymic personality attracted others, and this gave him a special ability to win over his political opponents. And when he couldn’t, his personality gave him the confidence to move forward with his proposals, and the cognitive flexibility to try out different ideas. He didn’t constantly calculate the political risks, looking at potential consequences, as normal people do; he acted on intuition, with the willingness to change course later if needed. Perhaps it takes this kind of hyperthymic man to have the resilience, indeed the courage, to simply close all banks, without anyone’s permission, when necessary; it is doubtful he would have delayed in raising a debt ceiling.

Our current president seems the epitome of normality — “no-drama Obama” — cool, calm, collected and committed to rational compromise. How much is reality and how much is packaging remains to be seen. But maybe, in times like these, a little abnormality in our leaders is what we need.