A long time ago, my go-to books when traveling were always mysteries — preferably Agatha Christie. Christie’s books are engrossing, delightful and just about the right length for a four-hour flight. They require very little brainpower. Also, there are lots of them, and it took many years and many trips to get through them all. (Actually, I’m not sure if I ever did.)

My love for Agatha faded over time — after a while those charming English villages start feeling a bit claustrophobic — but I still read fiction, mostly, when I’m traveling. During the rest of the year, I read almost nothing but nonfiction — memoirs and biographies by the zillions, as well as other books of narrative nonfiction. For me, fiction — even serious literary fiction — brings with it a lightness that says, “I’m not on the clock! My time is my own! Let’s go somewhere fun!”

So I was quite interested when, a few weeks ago, a friend sent me a clipping from a recent issue of Smithsonian magazine that showed the results of a study of vacation reading.

The Smithsonian editors examined more than 200,000 Goodreads reviews — probably not a scientifically sound approach, but still interesting — and then broke down the results by title, genre and city. They found that fantasy and sci-fi represent the most popular genre across the country for summer reading — nearly 30 percent overall, and No. 1 in Los Angeles, San Francisco, Phoenix, Boston, Chicago and New York City. (New York by a hair — just a percentage point or two ahead of young-adult.)

Second-most popular nationwide were young-adult books.

Mysteries didn’t even warrant a blip nationally, although they’re still popular for travelers heading out of Phoenix, Dallas and San Francisco. This really surprised me — what’s more engrossing than a good mystery? Where are all the Agatha Christie lovers? But there you go. Times change.

So what do traveling Minneapolitans read? (St. Paul isn’t on the list. Or maybe it’s folded into Minneapolis. In which case, thanks, Smithsonian.)

Minneapolis readers are, as you might expect, measured. No one genre stands out — fantasy, young-adult and romance each hover right around 20 percent. (Unlike in Miami, where almost 50 percent of the travelers are reading romance novels.)

No. 1 for Minneapolis travelers, though, is this: nonfiction. We are the only ones.

According to the Smithsonian study, about 26 percent of travelers out of Minneapolis (and possibly St. Paul) carry along a nonfiction book to while away the time.

Such a practical bunch we are. Perhaps we are reading serious historical tomes about the places we are heading, or weighty biographies of the famous people whose graves we plan to visit.

But I think we should test this theory.

September is looming, and the summer travel season is winding down. Did you read anything great during your vacation? Anything you’d recommend to fellow travelers? (Was it nonfiction?)

Do you prefer a specific genre when you’re headed for the airport? (Is it nonfiction?)

As always, send me an e-mail at books@startribune.com. I’d love to hear your thoughts. We’ll round them up and get to the bottom of this. If only I had some vacation time coming — suddenly I’m hungry for a good Miss Marple.

Laurie Hertzel is the Star Tribune’s senior editor for books. On Twitter: @StribBooks. On Facebook: facebook.com/startribunebooks.