Consumer DNA tests are genuinely useful tools — and widely misunderstood ones. Knowing what each kind of result actually means saves a lot of wrong conclusions.

What DNA does well

  • Cousin matching. The most powerful feature: the test finds living people who share segments of DNA with you, with an estimate of how close the relationship is. A strong match is real biological evidence — especially valuable in adoption searches and where records are thin.
  • Breaking specific deadlocks. DNA can confirm or rule out a suspected parentage where the paper record is silent or ambiguous.

What DNA does poorly

  • The ethnicity pie chart is a statistical estimate against reference populations — interesting, but approximate, and it changes as the companies update their models. It is not a documented family history.
  • Names, dates, places, and stories. DNA says that you’re related to someone; only records can say how — who the shared ancestors were, where they lived, what their lives held.
  • Other people’s attached trees. Matches often come with member-built family trees, and these inherit all the errors of unverified trees everywhere. Treat them as hints, never as conclusions.

The right way to use them together

The working rule in serious research: DNA suggests; documents prove. A match points toward a connection, and then civil registers, censuses, and church books establish the actual chain of people. Our own research is documentary — every conclusion in a Sapling report traces to a written source — and if you’ve tested, what you’ve learned can be a useful clue to share when your project begins. One consideration before testing: you’re sharing biological data with a private company, and discoveries (an unknown half-sibling, an unexpected parentage) can’t be un-learned. Most people are glad they looked; it’s worth deciding on purpose.

If DNA raised a question, records can answer it

Many clients come to us precisely because a test surprised them. Tell us what you found in the free assessment, and we’ll tell you honestly what the records can establish.

Sapling.Family is a family-history research service led by Professor Cisco Bradley, a historian at Pratt Institute. Every project begins with a free assessment of your family’s records. Browse all our guides, or explore a complete sample report.