We live in the future.

How do we know? Well, we can order a DNA test, mail in a bit of saliva, and get results that show our ancestry in just a few weeks.

There’s just one problem. The technology doesn’t appear to be there yet. Maybe we’re not as far into the future as we thought.

An investigation by Inside Edition aimed to find out how much we can trust leading brands of DNA kits. They got some help from three sets of identical triplets. Just to be sure, they added one set of identical quadruplets to the experiment. They handed each group of siblings a DNA kit from a different provider, watched them spit into the cups, and mailed off the samples. Then they waited.

By the time the tests were in, the triplets were all eager to see their results.

As we all know, twins should have identical DNA, right? If so, then many of these tests were terribly flawed.

In the Inside Edition experiment, one triplet was found to be 11 percent French and German. The test results claimed that one of her sisters was 22.3 percent French and German, while the other was only 18 percent descended from those countries.

Another set of siblings found that they were all descended from natives of the British Isles. However, the tests showed one sister as being 59 percent British, another 66 percent, and the third 70 percent.

The quadruplets showed nearly identical results.

So did the third set of triplets.

Lisa Guerrero from Inside Edition appeared with one set of triplets on TV’s The Doctors to discuss the findings. The host of the show, Dr. Travis Stork, explained what he saw as the problem with the varying results:

“I think the answer here is that we’ve come so far in terms of genetic testing, but you can’t just spit in a cup and have every single answer that you are looking for.”

There’s another possibility, of course.

We might have been wrong about identical siblings having identical DNA.

A 2008 study, summarized in this article from The New York Times, suggests just that. Researchers at the University of Alabama collaborated with scientists from universities in the Netherlands and Switzerland on this landmark study.

They looked at the genes of 10 pairs of identical twins. They expected the only genetic differences to be “epigenetic,” meaning gene expressions that are activated or suppressed by environmental factors throughout life.

What they found was very different.

Jan Dumanski, a genetics professor at the University of Alabama at Birmingham, worked on the study.

“When we started this study, people were expecting that only epigenetics would differ greatly between twins,” Dumanski told The New York Times. “But what we found are changes on the genetic level, the DNA sequence itself.”

It’s likely that mail-order DNA tests have some degree of inaccuracy, but it’s certain that we don’t understand everything about human genetics, either. Maybe the flaw was in our understanding, not the tests.

Either way, we’re looking forward to a future in which these things are all cleared up. In the meantime, check out the Inside Edition experiment below.