There's a word for Rahm Emanuel, according to John Gartner, Ph.D., an assistant professor of psychology at Johns Hopkins who published a psychological profile of the White House chief of staff in this month's Psychology Today. It's hypomanic.

(Gartner, coincidentally, is an expert on the term; he authored The Hypomanic Edge: The Link Between (A Little) Craziness and (A Lot of) Success in America in 2005, as well as a psychological biography of Bill Clinton this year.)

As the word suggests, it's a lesser form of mania, somewhere short of manic depression, one that carries with it a host of advantages, as well as a few drawbacks. Among the former, as Gartner outlines: energy, drive, confidence, creativity, and infectious enthusiasm--shared by the likes of Alexander Hamilton, Andrew Carnegie, and Emanuel's former boss Bill Clinton.

The drawbacks: overconfidence, irritability, and "especially impulsivity that often pitches the hypomanic into hostility. Drives are heightened and impulse control is weakened, making the hypomanic brain like a Porsche with no brakes," Gartner writes. It "runs in families with bipolar disorder."

Gartner suggests it's also a distinctly American trait, a part of the immigrant psyche in its "restless ambition" (Emanuel's own father immigrated from Israel):

The hypomanic temperament, like manic depression itself, is unusually common among immigrants. It's their restless ambition that makes them get up and go to a new place--which is why hypomania fuels the American temperament in general, as well as the innovation that has made America an entrepreneurial haven.

Emanuel, he of the fabled swearing and aggressiveness, who rose in his profession to become the top political combat tactician in the land, became this way in large part due to his family dynamic, Gartner suggests--with two brothers just as smart and aggressive as he is, not just to foster competitiveness and sharpen the younger brother's wit, but to remove the air of superiority that hyperintelligence breeds, and to develop a capacity for strong fraternal relationships--like the one he now enjoys, Gartner suggests, with President Obama.

Lore of Emanuel's personality has become as big as the storied personality itself. And, as Gartner notes, Emanuel has made efforts to tone it down. In a recent interview with NPR, he was actually, contrary to everything we've been told about how he is, legitimately soft-spoken.

Now, thanks to Gartner, we know the clinical term for all of this.

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