DNA tests for IQ are coming, but it might not be smart to take one

DNA tests for IQ are coming, but it might not be smart to take one, by Antonio Regalado.

Ready for a world in which a $50 DNA test can predict your odds of earning a PhD or forecast which toddler gets into a selective preschool?

Robert Plomin, a behavioral geneticist, says that’s exactly what’s coming.

For decades genetic researchers have sought the hereditary factors behind intelligence, with little luck. But now gene studies have finally gotten big enough — and hence powerful enough — to zero in on genetic differences linked to IQ.

A year ago, no gene had ever been tied to performance on an IQ test. Since then, more than 500 have, thanks to gene studies involving more than 200,000 test takers. Results from an experiment correlating one million people’s DNA with their academic success are due at any time. …

Each genetic variable found so far has only a tiny effect, either weakly increasing IQ on average or weakly decreasing it. The trick to turning the discoveries into a personal DNA IQ test? Simply add up all the pluses and minuses you find in a specific person’s genome. …

As of now, the predictions are not highly accurate. The DNA variations that have been linked to test scores explain less than 10 percent of the intelligence differences between the people of European ancestry who’ve been studied. …

These types of assessments are called “polygenic scores.” And they’re quickly becoming a very big deal (see “10 breakthrough technologies 2018: Genetic fortune telling”). That’s because they work for any trait, including heart disease, diabetes, and schizophrenia—in all, more than 2,000 traits so far. …

MIT Technology Review found that genetic IQ assessments are already being offered by websites that provide information to people who’ve previously had their DNA measured by 23andMe or Ancestry.com. … The results come with disclaimers saying the results don’t mean much yet, because they predict only about 5 points of IQ. …

This is going to blow the cover for a whole lot of PC fantasies. The left will fight such tests … and perhaps ban them. But look what they can do:

Although it’s still taboo to talk about, some medical scientists are trying to figure out how to use the polygenic intelligence scores to pick the smartest embryo from an IVF dish, choose the best sperm donor, or discover fetuses at high risk for an expanded menu of cognitive disorders, including autism.

Dalton Conley, a sociologist at Princeton University, says as soon as the IQ predictions reach the double digits—something that could occur very soon—we will need to have a “serious policy debate” about such “personal eugenics.”