By Marina Wang

A new study has found that users of genetic ancestry tests such as ancestry.ca or MyHeritage tend to select which races to identify with based on preconceived biases.

“People often buy these genetic ancestry tests because they’re looking for a sense of belonging or to confirm a story that’s been passed down in their family,” said Wendy Roth, a sociology professor and the study’s lead author. “But if the test results don’t support what they want to believe, we found that people will often ignore the results or criticize them. We tend to cherry-pick the parts of our family story that we like most and want to emphasize.”

The study, published in the American Journal of Sociology this month, qualitatively surveyed 100 participants before and after taking ancestry tests. Rather than accepting all their test results, participants tended to selectively identify with ethnicities they thought were positive while disregarding others. Additionally, white participants were more likely to embrace new racial identities.

The study included the case of a man who identified as Mexican-American. When his ancestry test revealed Jewish, Celtic and Native American ancestries, he embraced his Jewish heritage while disregarding his Celtic background. “I always looked up to the Jewish people… I thought of them as higher than me,” he said.

Another female participant who was adopted always believed her birth parents had Native American ancestry. However, when her genetic test revealed no Native American background, she disregarded the test results and continued identifying as Native American.

However, Roth advised users to take the genetic tests with a grain of salt. “There are many ways in which genetic tests that tell you the percentages of your ancestry are misleading and they’re often misunderstood,” she said. “Some tests can be useful for helping people track down long-lost relatives who are genetic matches, if they’re lucky. But people who use these tests to determine their race or inform their sense of identity should be aware that this isn’t the right way to think about it.”