In the fall of 1972, when David Galenson was a senior economics major at Harvard, he took what he describes as a “gut” course in 17th-century Dutch art. On the first day of class, the professor displayed a stunning image of a Renaissance Madonna and child. “Pablo Picasso did this copy of a Raphael drawing when he was 17 years old,” the professor told the students. “What have you people done lately?” It’s a question we all ask ourselves. What have we done lately? It rattles us each birthday. It surfaces whenever an upstart twentysomething pens a game-changing novel or a 30-year-old tech entrepreneur becomes a billionaire. The question nagged at Galenson for years. In graduate school, he watched brash colleagues write dissertations that earned them quick acclaim and instant tenure, while he sat in the library meticulously tabulating 17th- and 18th-century indentured-servitude records. He eventually found a spot on the University of Chicago’s Nobelist-studded economics faculty, but not as a big-name theorist. He was a colonial economic historian – a utility infielder on a team of Hall of Famers.

Now, however, Galenson might have done something at last, something that could provide hope for legions of late bloomers everywhere. Beavering away in his sunny second-floor office on campus, he has scoured the records of art auctions, counted entries in poetry anthologies, tallied images in art history textbooks – and then sliced and diced the numbers with his econometric ginsu knife. Applying the fiercely analytic, quantitative tools of modern economics, he has reverse engineered ingenuity to reveal the source code of the creative mind.

What he has found is that genius – whether in art or architecture or even business – is not the sole province of 17-year-old Picassos and 22-year-old Andreessens. Instead, it comes in two very different forms, embodied by two very different types of people. “Conceptual innovators,” as Galenson calls them, make bold, dramatic leaps in their disciplines. They do their breakthrough work when they are young. Think Edvard Munch, Herman Melville, and Orson Welles. They make the rest of us feel like also-rans. Then there’s a second character type, someone who’s just as significant but trudging by comparison. Galenson calls this group “experimental innovators.” Geniuses like Auguste Rodin, Mark Twain, and Alfred Hitchcock proceed by a lifetime of trial and error and thus do their important work much later in their careers. Galenson maintains that this duality – conceptualists are from Mars, experimentalists are from Venus – is the core of the creative process. And it applies to virtually every field of intellectual endeavor, from painters and poets to economists.

After a decade of number crunching, Galenson, at the not-so-tender age of 55, has fashioned something audacious and controversial: a unified field theory of creativity. Not bad for a middle-aged guy. What have you done lately?