A middle-aged white man raises his sword to the skies and roars to the gods. The results of his genetic ancestry test have just arrived in his suburban mailbox. His eyes fill with tears as he learns that he is “0.012% Viking”. These are the scenes from a video advertisement for the TV-series Vikings.

This man is certainly not the only one yearning for a genetic test to confirm his Viking ancestry. A plethora of companies around the world market DNA-tests that promise to provide scientific facts about your identity. These companies often claim to provide a complete view of your ancestry, even though they in reality only compare your DNA with other customers in their database.

According to recent estimates, over 26 million people from across the world have purchased a genetic ancestry test. In the wake of this hype, researchers have begun to investigate how the tests affect our perceptions of ourselves. How do people make sense of a test result stating that they are, for instance, “35% Ashkenazi Jewish”, “27% British” or “4% western Asian”?

Some researchers have concluded that such tests make customers believe that humanity can be divided into biological races, and that customers see the tests as a way of discovering their “true” identities. Other researchers have argued that people use their test results selectively, “picking and choosing” the genetic data they find compatible with their personal desires and aspirations. From this perspective, taking a genetic ancestry test involves some level of creative interpretation.