Minutes into a Zoom interview with Henry Louis Gates Jr., he’s quoting Don King as he discusses two discoveries in season 12 of his PBS series Finding Your Roots: actress America Ferrera finding out one of her ancestors was a free mulatto of mixed African origin — and she’s a distant cousin of director Ava DuVernay — and actress Sanaa Lathan learning she’s the descendant of a wealthy white slave owner. 

“Only in America,” says the host. “Or since America’s [family is] from Honduras, I should say, ‘Only in the Americas.’ ”

Since 2012, the Harvard professor has hosted the TV series in which he presents famous figures, from Tina Fey to Deepak Chopra, with a book of their families’ layered maternal and paternal histories, which come together via DNA testing and research gathered by genetic genealogy expert CeCe Moore and a team of three full-time genealogists. The conversations are at once revelatory, emotional and judgment-free. “There’s ‘stuff’ on every family tree,” says Gates.

As a host, you’re not just relaying personal information to guests; they’re opening up to you about their private family stories. How much time do you spend with them before filming?

I meet the guests on set. But there is one exception. If you were our guest and we found out that, let’s say, your daddy wasn’t your daddy but your daddy didn’t know, I have an ethics protocol and we would reach out to your publicist and say, “We’ve learned something in our research that we need to discuss directly.” And everybody knows it’s not good news. It’s like when your doctor calls you the same day you had a blood test. You go, “Oh shit, this is not going to say you’re going to live to 120.” So I would say, “We’ve discovered something in the course of our research that is forever going to change your understanding of your family. Do you want to know or not?” And then you would say, “Yes, of course, I want to know.” And I would say, “The man that you called your father is not your biological father.” Or, more likely, “The man you called your grandfather” — like in the case of Joe Manganiello — “had no biological relationship to you. Your grandmother had an affair” — in his case — “with a Black man.” In fact, Joe has done so much subsequent research that we’re thinking about doing a special segment in season 13, half of which features all the stuff that we’ve learned about him because the research goes on. 

But on the other hand, I’ve had people who just said, “Hey man, thank you [I don’t want to know more].” People trust us. We’ve never had [an information] breach and we send them all of their research because this is their story. We’re not The Jerry Springer Show. When I think about how to generalize those who drop out, it’s because the party who, shall we say, made a complex decision within a relationship, is still alive.

How do you prepare for those conversations?

I’ve been a professor for almost 50 years, and I pride myself on using the classroom for difficult conversations, which prepared me for having these one-on-one conversations with people. One of my friends joked that I’m the only Black man in the world who makes white people feel better about having owned slaves. But I’m going to tell you something: The sad truth is everybody was guilty in the slave trade. Well over 90 percent of the Africans captured in Africa and shipped across the Atlantic were captured by African merchants and African elites. People don’t want to admit that, but it’s the truth. I also firmly believe that we are not responsible for the wicked things that our ancestors did. People’s lives are complicated, and I don’t think you should allow anyone, no matter what we find, to bully you about it. But on the other hand, there are amazing stories of triumph on everyone’s family tree. At the beginning of an interview, I ask people, “How do you think your ancestry has shaped you? Do you think you’ve inherited any traits from your ancestors?” Five hours later — and really each of these shoots is five, sometimes six hours — I ask them the same question. In many cases, like Téa Leoni, when we found out her mother was adopted, we found her mother’s birth mother and birth father — her birth mother was still living at the age of 98 — and then she connected with her half-siblings, and that was great. I hear from a lot of people saying thank you.

It was pretty great timing to have Delroy Lindo on this past season in the midst of his historic Oscar campaign. How far in advance do you book guests?

Well, I’ve been a fan of his since Do the Right Thing and I will say it’s not an exact science. We get so much celebrity outreach of really big people desperate to do the show, and sometimes we can do all the research in six months — one person, it took five years because they had a DNA mystery, and the only way you could solve that is if the link is in one of the publicly available databases. We cannot watch the Oscars and then pick somebody and two months later they’re on TV. On average, it takes six months at least to do the genealogical research.

Who’s on your guest wish list?

Beyoncé, Taylor Swift and Madonna — but I want Taylor and her fiancé [Travis Kelce]. I would like Clint Eastwood. I would love Jay-Z. I would love Gladys Knight. I’ve had dinner with [Barbra Streisand] a couple of times and she has said, “I’ll do it, but I’m not ready yet.”

How is AI affecting the field of genealogy?

The real revolution was digitizing. All of those censuses, birth certificates, death records, marriage records are online. So you can do a lot of research just from your computer now, but there’s always more research that can be done on the ground. I call [AI] my liquid encyclopedia. So rather than google stuff, I’ll just type in, “Tell me about so-and-so.” And that’s how we use it for research. But you can’t say, “Give me the family tree of the pope.” I can imagine that you’ll be able to ask it, “Give me the records of every child born in Honduras in 1819.” You can’t do that right now, but I’m sure that it’s coming. It will only enhance research.

What has it meant to you to do this work now for 20 years, dating back to the PBS series African American Lives in 2006?

When I conceived the series, I swear to God, it never occurred to me that we’d be doing anyone other than African American people. I wanted to give them their buried roots, their lost history because of slavery. But by 2009, I realized everybody has a hidden family history because we are a nation of immigrants — our African ancestors were unwilling immigrants, but they came from elsewhere. I always tell my guests a quote that one of my heroes, Stephen Hawking, gave in a lecture at Harvard in 2016: “It is the past that tells us who we are. Without it, we lose our identity.” He was talking about the age of the universe, but it’s true for each of us as individuals, and what we are doing is giving every guest on Finding Your Roots their lost, complex past.

This story first appeared in a June stand-alone issue of The Hollywood Reporter magazine. To receive the magazine, click here to subscribe.