The son of New Deal Democrats, Summers could recite the Kennedy cabinet from memory and spent a weekend glued to the television set when the president was assassinated.

But, for all that Summers and family emphasize the ordinary aspects of his childhood in Merion, there are details, that—while far from being the clue to understanding Summers’ speedy rise through the ranks—at least give it a more sensible context.

Nature. Summers was born to two economists. Both taught at the University of Pennsylvania. His father specialized in statistical modeling and the heavy-duty mathematical work, while his mother was interested in practical issues, like urban economics.

His uncles were the dons of modern economics, and won Nobel Prizes only two years apart. Kenneth Arrow, a long-time Harvard economist, is his mother’s brother, and Paul Samuleson of MIT, was his father’s brother (Summers’ father and another uncle had changed their surnames).

Given the heavyweight pedigree, when Larry decided to go into economics, friends were quick with the jokes. The Summers family had gotten what all parents dream of: A son who becomes a doctor (Richard), a son who goes into law (John), and of course, the son who goes into the family business.

And Nurture. More than genetics caused the Summers family windfall. Best friend Richard Neff remembers the intellectual climate of the Summers household as “a hotbed of intellectual activity. Every day they solved a different world problem,” he says.

Neff spent hours at the Summers residence, and enjoyed the charged atmosphere—to a point. “I liked going over there. I also liked leaving,” he says.

Summers possessed a college-level vocabulary in elementary school. He was also remarkably well aware of what was going on in the world around him. At age 10 he was on a sports radio game show, and the show ran out of questions before its airtime was up. Neff recalls that the host asked Larry what was on his mind. “I think I expressed the view that Red China should be in the UN and that the U.S. shouldn’t be in Vietnam,” Summers says. While Summers speculates that the argument wasn’t very well thought out or articulated, Neff cites the moment as “classic Larry.”