These people took DNA tests. The results changed their lives

What happens if your genome hides a secret about your ethnic identity? Jenny Kleeman, presenter of The Gift, meets a few people who made surprising discoveries to find out.

Kara Rubinstein Deyerin bought her father an at-home DNA test for Christmas in 2017 because she wanted to find out where exactly her ancestors came from in Africa. She had already traced her family tree back to three slave brothers from Texas, but her dream was to take her three sons to Africa, to do what she calls "a finding-our-roots tour".

It was an exciting gift, but not particularly original. Kits from companies like AncestryDNA, 23andMe and MyHeritage have become the go-to Christmas present for the person who already has everything. Worldwide, tens of millions of us have sent our DNA off to be tested, including one in 20 British people, and more than 26 million Americans. For many, the appeal comes from the tantalising promise that our genes can reveal who we really are, and where we come from. That was certainly the case for Rubinstein Deyerin. She bought a test for herself, as well as her dad.

Growing up in Seattle with a white mother and a black father, Rubinstein Deyerin had experienced racism for as long as she could . Kids at school called her "Oreo", "half-caste" and "zebra". Filling in forms at her elementary school, Rubinstein Deyerin's mother ticked the box that said that her daughter was black.

"There's the one drop rule in the United States where if you have one drop of African ancestry, then you were considered a person of colour," says Rubinstein Deyerin. "She thought it would help me get into some programmes." Based on Rubinstein Deyerin's appearance, the school questioned her right to check the box. But race and ethnicity depend on much more than skin colour, Rubinstein Deyerin says. "You can't look at somebody and know their ethnicity."

The results of Rubinstein Deyerin's own DNA test came just before her 44th birthday, in the form of a pie chart. Finnish, German and English ancestry took up one half of the pie, and the other half estimated her to be 50% Ashkenazi Jewish. The man who raised Rubinstein Deyerin wasn't her father – and she had no African American heritage, after all.

Rubinstein Deyerin now belonged to an ethnic group she knew nothing about. "I'd never heard of the term Ashkenazi before. I didn't even think my mum had ever met a Jewish person before." She smiles. "Obviously she did once."

Five years on from these revelations, she wears a Star of David pendant in our Zoom call. She's embraced Reform Judaism and recently returned from spending a few months in Israel. She's adopted her biological father's name as hers – hence the Rubinstein part of her surname – even though he ed away more than 10 years before she took the DNA test, and his family don't want a relationship with her.

With no one to help her navigate her newfound Jewish identity, Rubinstein Deyerin had to find it on her own – but when she did, she felt an immediate connection. "The first time I went to Temple, I sat in the back and I heard the Hebrew. Something just clicked for me."

As I discovered while making The Gift, my series for BBC Radio 4 and BBC Sounds, people who take DNA tests on a whim can end up having to reckon with life-changing results. What do you do when you discover you're a different ethnicity to the one you grew up believing you were? How much of our heritage comes from our genes, rather than our upbringing? And how much can we actually trust what these tests tell us about who we are?

In an age of identity politics, your racial identity can give you certain claims in the world, giving you access to certain spaces, and excluding you from others. Being part of a minority group may mean you're more likely to face discrimination, brutality and even genocide, but, as Rubinstein Deyerin's mother knew, it might allow you to qualify for certain programmes, scholarships or even fortunes: people from the Native American, Wisconsin-based Ho Chunk Nation are eligible for a $200,000 (£164,000) share of tribal wealth when they graduate from high school, so long as genetic test results show they have a requisite amount of Ho Chunk DNA.

But there is a lot more to racial identity than genes. Mark Thomas, professor of evolutionary genetics at University College London in the UK, is a longstanding critic of genetic ancestry testing. "Genetic ancestry testing has a rather chequered history of people making exaggerated or plain ridiculous claims in the past," says Thomas. Things have improved in the years since he first raised questions about the validity of these claims, he adds. "The big companies today don't do that so much. But I don't like these companies using the term 'ethnicity' because your biological ancestry is not your ethnicity – ethnicity is a socially defined category. I feel that they are using the word as a euphemism for race. Race is also socially constructed, but ideas about race traditionally were based more on ancestry. It just feels a bit icky – they are not biologically meaningful categories."

The companies behind at-home DNA tests have pages on their websites that concede that their ethnicity estimates are imperfect. MyHeritage emphasises that these are simply estimates, with limitations: boundaries are fuzzy, and ethnicity estimates can only go back so far.

23andMe lists several "wrinkles'" that make their estimates imperfect: people usually have multiple ancestries, and biomedical research typically focused on their DNA of people of European descent, meaning there is far less available data from diverse populations. It also emphasises that its test results will offer details about "genetic ancestry" – that you share recent ancestors with a group of people who identify as belonging to an ethnic group – rather than an estimate of ethnicity or race. It highlights, for example, important distinctions between a test result showing a DNA match with Indigenous American populations and claiming Native American identity. "23andMe does not conflate the concepts of ethnicity and genetic ancestry," a spokesperson for the company adds. "We've always understood the importance of distinguishing these concepts clearly."

AncestryDNA points out that ethnicity reports come from comparing DNA to a reference of self-reported ethnicities, which are not distinct biological categories, and that its results may be less than perfect in estimating where your ancestors came from.

But all three companies highlight the ethnicity and nationality component of their results in their marketing. And that's often what gets consumers interested. 

Jacobsen had been wondering about her heritage ever since an offhand comment was made to her 50 years earlier. She grew up in Queens, New York, the daughter of Danish immigrants who came to the US in 1947.

"My parents were swingers," she tells me. When she was 16, her mother's boyfriend had casually remarked that Jacobsen's biological father was black. Until that point, Jacobsen had no reason to doubt she was anything other than 100% Danish. "I was stunned. I didn't know what he was talking about," she says. "I looked white."

Discussing the comment with her Danish father later that evening, he told her she looked too much like her paternal grandmother for it to be true. But it sowed a seed of doubt that remained with Jacobsen until she was in her late 60s. Now, settling the questions was as easy as spitting into a vial and sending her DNA off for analysis.  

When the results came in, Jacobsen's pie chart estimated she was 25% West African. "Clicking on the email and looking at the results was a validation of a question that I had had for all those 50 years."

She threw herself into learning all that she could about her ancestry. She had a DNA match with a first cousin on 23andMe, and messaged her through the site. Together, they worked out that her biological father was a dancer named Paul Meeres Jr, Jacobsen trawled the internet for any information she could find about him, eventually writing a memoir about her search for her genetic identity. At the same time, she embraced her new-found African heritage. And just like the man in the Ancestry commercial, Jacobsen changed her clothes: she experimented with wearing a headwrap, known as a "gele" in Nigeria, and studied YouTube tutorials to learn how to tie it. She went to a local clothing store and bought her 28-year-old son, Alek, a dashiki – a colourful West African shirt.

But Alek didn't feel comfortable wearing it. "It was a beautiful article of clothing, but I thought it was a joke," he says. "It's definitely not something that I could wear. It was a costume."

Alek explained to his mother that her experiments with African culture were a kind of appropriation. No matter what her DNA results showed, he said, if a person presents as white, they can't experience the world as a black person. "One of the things about race is it's not about yourself. It's more about how society treats you."

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