It's All Relative
Adventures Up and Down the World's Family Tree
By A.J. Jacobs
Simon & Schuster. 336 pp. $27

Reviewed by Eric Weiner

nolead ends A.J. Jacobs concedes from the outset of It's All Relative that he has an agenda: world peace. Studies find that we treat people better if we know they're family, so why not hijack this tendency by tricking our brains into believing everyone is kin? Only it's not a trick. As Jacobs demonstrates, we are all family. ("Whether we like it or not," quips Henry Louis Gates in a cameo.) Go back far enough, and we all share a common ancestry.

Jacobs' ancestral journey begins the way all great genetic spelunking begins these days: by spitting into a tube. His DNA results are, at first blush, remarkably boring. Jacobs is a plain-vanilla Ashkenazi Jew, with a smattering of "other." Thankfully, he isn't deterred. He digs and digs. He tracks down relatives, distant and really distant. He scours old newspaper clippings. He mines a massive database of tombstones called Find a Grave. Soon, he unearths a family history "drenched with booze" and replete with tales of courage and cowardice, virtue and pettiness.

He attends a twins convention; tracks down a real McCoy, of the famous Hatfield-McCoy feud; and discovers that he, like nearly all of us, is part Neanderthal. He makes predictable but rewarding pilgrimages to Ellis Island and Salt Lake City, home of the Mormons, those "genealogy rock stars."

Along the way, he manages to prove Tolstoy wrong. All happy families are not alike. They come in more flavors than ever. Today, we don't so much inherit family as create it. "You no longer need to share chromosomes to call yourself kin," concludes Jacobs.

Nestled within It's All Relative is a project, and an ambitious one. Jacobs wants to hold the world's largest family reunion. The Global Family Reunion, he calls it. The plan is to gather a few thousand of his relatives and celebrate not only their kinship but the very notion of kinship.

Jacobs is the Zelig of genealogy. There he is, doing the warm-up act for Donny Osmond. Now he's hanging with his very famous, very distant cousins, from Daniel Radcliffe to George H.W. Bush to Ricky Gervais. Jacobs defends this sort of celebrity genealogy - epitomized by such TV shows as Who Do You Think You Are? - on the grounds that "they inspire people to trace their own pasts." Perhaps. Or maybe it's just a sophisticated way of justifying our voyeurism.

Jacobs, thankfully, tempers his Kumbaya tendencies with some hard-nosed questions. Does knowing your ancestry expand your circle of compassion or shrink it? The jury is out. An anti-Semite discovers he is part Jewish and reforms his ways. White supremacists hold online contests to see who has the highest percentage of European descendants.

Jacobs doesn't shy away from this fact, exploring the dark side of genealogy: not only relatives with checkered pasts (one of his in-laws served time in Sing Sing prison for murder) but privacy concerns and the very real danger that all of this DNA testing may render us more tribal, not less.

Jacobs treats the reader like family. He shares his every neurotic twitch surrounding the Global Family Reunion, from the catering requirements (potato salad for 3,000) to the sponsors (fickle) to the deliciously ironic dispute among Sister Sledge (slated to perform their ode to kinship, "We Are Family"). Despite his ineptness, or perhaps because of it, I found myself rooting for him and his quixotic project. Did I believe that Jacobs' gathering of a few thousand cousins on a soggy Queens field would change the world? Not for a second, but it was fun to watch him try.

Jacobs is best endearing when he drops the comedy armor and gets real. With the Global Family Reunion approaching rapidly, he writes: "I've never been in charge of a cause that people actually believe in. It's terrifying. About half the time I feel like a fraud."

By the end of It's All Relative, Jacobs feels like, well, family. Mostly endearing, occasionally annoying but always well-intentioned and, in the final analysis, indispensable. Now if only he'd call more often.

Weiner is the author, most recently, of "The Geography of Genius: Lessons From the World's Most Creative Places." This review originally appeared in the Washington Post.