In his new book, It’s All Relative: Adventures Up and Down the World’s Family Tree, journalist A.J. Jacobs recounts his investigation into the DNA and histories that link almost every human on the planet. His deep dive led him to meet some very famous — and very extended —cousins, including Olivia Wilde and President George H.W. Bush.
“We were all told since we were kids that humans are all one big family, but now it’s so concrete you can actually see how we’re all related to almost anyone on earth,” Jacobs tells PEOPLE in an exclusive interview. “It makes you feel like you’re part of something bigger. It’s like six degrees of Kevin Bacon, but everyone is Kevin Bacon.”
For It’s All Relative, Jacobs delved into science (scientists are creating a Global Family Tree that shows how all of the seven billion humans on earth are linked to the same ancestors: Mitochondrial Eve and Y-chromosomal Adam) and interviewed a diverse array of groups (like Daughters of the Revolution; the Lilly family, who threw the biggest family reunion on record; and even the founder of an online group that supports first-cousin romantic relationships) to understand how genetics and family play out in the modern world.
“I don’t expect world peace to break out when people read my book or go on these sites, but there is evidence that [knowing how humans are all related] actually makes us a little more kind and open minded toward each other,” Jacobs explained.
“I do love that there are some white supremacists who are taking DNA tests and they’re finding out that they’re not purely white,” he said. “They’re freaking out. I enjoy their discomfort so much.”
For Jacobs, realizing his familial connections is a joy and has greatly widened his social/professional network. He successfully met distant relatives Ricky Gervais and Wilde, and posed for photos with them holding a sign reading “I am a cousin.”
“You want to meet someone? Just figure out how they are related to you,” Jacobs writes in his book, which is exclusively excerpted in this week’s PEOPLE. “It worked for me, even when the link was almost absurdly distant. I wanted to interview former President George H.W. Bush about his family. I was told he wasn’t doing interviews, but I explained that I was related (he’s my first cousin once removed’s husband’s third-great-grandmother’s third-great-nephew). Next thing you know, I’m chatting up the president over a hamburger lunch.”
Some other celebrities he’s related to include: Rachel Weisz (his 12th cousin), Hillary Clinton (his 8th cousin), James Spader (the ex-husband of his first cousin once removed), and some other pretty significant figures.
For the full excerpt, pick up this week’s issue of People, on stands now.
“I love being related to Abe Lincoln and Albert Einstein, of course,” Jacobs told PEOPLE. “But also William Rosenberg, founder of Dunkin’ Donuts.”
Beyond his own family tree, Jacobs also taught celebrities about their heritage. After finding an oral history by Ludacris‘ great-grandmother Bertha Craig, he revealed to the rapper that he is part Jewish. (Craig believed that her father was Jewish).
“So I revealed that to [Ludacris] for the first time. He was like, ‘Wait, I’m Jewish?'” said Jacobs, who is also Jewish. “I was like, ‘A little bit. Mishpokhe,‘ which is the Yiddish word for family.”
“He was surprised,” Jacobs said. “But happy that he had this diverse background.”
It’s All Relative is on sale now.