Aggregated News

A close up of the face of a Rottweiler smiling with its tongue out against a background of green grass.

A DNA test found that I’m 72.3% of Ashkenazi Jewish descent, thanks to ancestors from Ukraine. I expected as much.

It also determined that I’m 11.3% Scandinavian, 7.8% Spanish or Portuguese, and 3.1% Italian.

This is unexpected, both to me and my parents, who insist there are no secret Swedes or Spaniards in our family tree. I gesture a lot when I speak, so who knows about the Italian thing.

Another DNA test found that my family’s dog, Teddy, is part pit bull, which comes as no surprise. Many rescue pooches have pit bull roots.

The test also says Teddy is to a great extent of Saint Bernard stock, which maybe you can see if you really squint, but which, to my mind, is a bit of a stretch. Rottweiler maybe, or mastiff — he’s a big, strong dog — but Saint Bernard?

These results raise questions many people ask (or should ask) when they approach the multibillion-dollar business of home DNA tests, which are readily available online:

Are they accurate?

Are they worth the money?

What good is the...