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23andMe Made Me Rethink My Identity—Twice

As my DNA profile changed over time, so did my concept of self

Peter Cho
Peter Cho
Jan 23 · 6 min read
Photo courtesy of the author

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One morning in spring 2017, I spat into a tube containing a stabilizing solution, packed up the kit, and dropped it into the mail to return to 23andMe. A few weeks later, I would get a report detailing where my ancestors come from. I was not expecting any surprises, but merely a confirmation of what my parents have always told me: I am wholly Korean.

When I got the results online a month later, I was shocked. The report said I was only 58 percent Korean, with ancestry percentages from both China and Japan in the high teens. According to 23andMe, it was extremely likely that I had a full-blooded Chinese and a full-blooded Japanese grandparent, great-grandparent, or great-great-grandparent. These relatives would have been born in the later part of the 1800s or first few decades of the 1900s. They would have lived less than 100 years ago and may have been alive when I was born. This was news to me, given everything I had learned about my family. Who were these mystery relatives, and what secrets were my family hiding?

Illustrations: Peter Cho

At Thanksgiving, I broke the news to my parents, explaining that 23andMe predicted a 100 percent Chinese and 100 percent Japanese ancestor, just one to three generations away from them. The data indicated the Japanese relative was likely from my father’s side, which made me think the Chinese ancestor would be on my mom’s. I explained some of the science behind the report. I knew the company extrapolated ancestry results by comparing my DNA against the genetic information of other people who have taken the test. If fewer people like me had contributed their saliva, the database would have less genetic information from my part of the world and the results could be less accurate. But the numbers were so precise, and the wording—extremely likely—made me trust the science.

My parents were having none of it. “No, no, no—you are full Korean,” my mom said. “We know my line and Dad’s. We’re 100 percent Korean.” She was sure of it, and she wouldn’t entertain the possibility that a non-Korean could be part of our lineage. Done with the conversation, she left the room.

My dad is a doctor by training and more practical in his thinking. He contemplated for a few minutes, then finally smiled and shrugged. “Well, you never know,” he said. We left it at that.

In my experience, Koreans tend to be proud, stubborn people. Over the past two millennia, Korea has been colonized by neighbors to the west and east. But despite outside pressures, Korean people have maintained their culture—customs, language, food, music, traditions—over many centuries, and they are protective of their distinct identity. We come from a family that prides itself on being full-blooded. The Chos, I was told, keep an ancient book recording our family tree. The book also prescribes either the first or second part of our given names, so every child’s name has one syllable in common with every other Cho in their generation.

I spent a summer in Korea when I was 19, studying at the language institute at Yonsei University. These programs are colloquially called “Love Boat” because Korean emigrant parents send their college-age children hoping they will pair up with other second-generation Koreans. When my grandfather—my harabeoji—saw me off at Gimpo Airport at the end of the summer, he explained how important it was to marry a Korean woman. He was not, however, most concerned with pure bloodlines. “Think of your family and hers,” he told me. “Finding another Korean will make life for everyone easier.”

Knowing the tumultuous history of the Korean peninsula, I wondered whether all the people who think of themselves as Korean might have mixed ancestry. I conducted some research by bingeing on videos of BuzzFeed staffers learning their 23andMe results. Gene thought he was 100 percent Korean, and his results pretty much verified it, 97.3 percent. Daniel believed his mom was 100-percent Korean, and his relative percentage was pretty close, 45.5 percent. My numbers were off. Thanks to YouTube, I learned it was just me.

Maybe this explained why East Asian people I have met over the years have guessed I was Chinese or Japanese. Many were surprised when I said I was Korean. I wondered if it was my mixed heritage that made me so hard to place. My 23andMe results led me to tell a different story about myself and made me feel like I had a special secret, a mystery that I might one day uncover.


Months passed, and I grew comfortable with this new information about my past and identity—until last week, when I logged into my 23andMe account for the first time in a year and a half. An ancestry report marked “New” was featured on my dashboard. New? I wondered. How could my ancestors be new? According to the updated results, I am now 94.5 percent Korean and 4.8 percent Japanese. (My most recent ancestor from Japan was most likely from five to eight generations ago.) The Korean ancestry page had been updated since my last visit to the site, filled with tips on the food, culture, and sites of Korea—banchan, Buddhist temples, and Namsan Tower—all of which was familiar and comforting.

The new report restored 36 percent of my Korean-ness and indicated that my parents were right. But I also lost the Chinese and Japanese great-great-grandparents I never knew.

What accounted for this increase in my Korean percentage, reduction in my Japanese ancestry, and erasure of my Chinese-ness? According to a blog post, 23andMe improved the precision of its African and East Asian ancestry results in 2018 based on the contributions of its customers and newly available public data. A FAQ on the 23andMe site explains that because its reference populations and algorithms are always being revised, it prefers to call the ancestry composition “a living analysis of your DNA.” The scientific details page of ancestry results even includes a “Change Log” with a record of recalculations of when your results are made, although it offers no links to previous reports. Only your latest calculation, hopefully the most correct one, is available online.

“For the most part, these changes should be minor,” they claim. For me, going from 58 to 95 percent Korean was a major shift. It cleared up a story about my life and heritage that confused me for months, and it resolved a lingering dispute with my parents. But the even bigger surprise was that I allowed a tech company (one that has had its share of controversy) to rewrite the narrative of my family that was passed down to me over many generations.

This episode also leaves me feeling embarrassed that being a full Korean is a bit of a letdown. Isn’t it more interesting to have a mysterious impostor from Japan or China in my bloodline? Why is the story my parents told me all my life less compelling than the one 23andMe peddled?

When you spit into a tube and send it away, part of you is hoping the results will be unexpected or even revelatory. You may learn there are family secrets waiting to be uncovered, hidden truths, and mysteries about your recent past. Or you may find that the story you’ve always believed to be true is corroborated by the percentages listed in your ancestry report. If you’re really lucky, the choose-your-own-adventure story about who you are and where you come from will follow both these forked paths, and you’ll get to experience both endings. It will leave you to wonder, Why am I so easily swayed? How can the story I tell about myself be so easily rewritten?

Peter Cho

Written by

Peter Cho

Head of Design at Pocket. Formerly Medium, Google Project Ara, Inkling. Early joiner, late adopter.

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