Spoiler alert: A.J. Jacobs admits near the end of “It’s All Relative” that his Global Family Reunion failed “to end all wars and racism. At least as of press time.”

So Jacobs — in case you aren’t familiar with his previous bestsellers such as “The Year of Living Biblically” or “The Know-It-All” — is a humorist. But there is sincere optimism alongside Jacobs’ humor, and while he does not end all wars and racism, the news isn’t all bad.

The idea for the Global Family Reunion is born after Jacobs is contacted by an eighth cousin who has drawn his family tree to 80,000 members and hosted a reunion of 3,000. Despite having no event-planning experience, Jacobs imagines he can set a world record for the largest family reunion.

And so begins a sequence of successes and misadventures that Jacobs recounts in 46 breezy chapters.

In one episode he books Sister Sledge to perform its hit “We Are Family,” only to learn that one of the sisters is now estranged from the group. This irony puts Jacobs’ optimism (we are all related) in sober context (being related doesn’t always mean getting along).

But happier examples are more plentiful. One comes in the form of a “radical nationalist politician and outspoken [anti-Semite] in Hungary [who] found out he was part Jewish. He abandoned the far right and became an activist against discrimination.”

Of course, in this age of fake news, some may respond to an example such as this as one white supremacist did when he claimed that “DNA services are ‘rigged’ to spread ‘multiculturalism and make whites think that they are racially mixed.’ ”

For all the fun Jacobs has in his excursions into his family’s ancestry, Mormon genealogical archives, DNA testing, the evolution of our species and dozens of other related topics, his project is a serious one. At a time when racial essentialism is finding favor across the political spectrum, “It’s All Relative” offers the timely reminder that we are all a blended family.

And if you think being racially mixed is scary, you’ll really have to bury your head in the sand when Jacobs reports that “All humans today, with the exception of some sub-Saharan Africans, have Neanderthals in their family tree. … In all likelihood, you aren’t just one race. You aren’t even one species.”

 

Scott F. Parker is an author and book critic in Montana.

It's All Relative
By: A.J. Jacobs.
Publisher: Simon & Schuster, 336 pages, $27.