Can DNA Tests Predict Intelligence or IQ?
With the emergence of big data and machine learning, we’re now able to do all kinds of things that we couldn’t do before. While genetic testing started out as something you could use to find out if your dad is actually the milkman, it has now progressed into other areas. We recently wrote about how polygenic risk scores are being used to predict everything from a person’s height to their susceptibility towards mental illnesses. In a piece we wrote a while ago on genetic modification at the germline, we discussed a topic that is as equally fascinating as it is controversial – can DNA tests predict intelligence or IQ?
Can DNA Tests Predict Intelligence?
If you’re not familiar with twin studies, you should read up on this fascinating topic. Since identical twins share nearly 100% of their genes, differences between two identical twins can be largely attributed to environmental differences. If a pair of twins were raised in separate environments, the differences they exhibit should be attributed to nurture, not nature. This unique method allows researchers to identify how DNA affects traits.
One man who leads a long-term twin study consisting of 13,000 twins is an American by the name of Robert Plomin, a deputy director of the MRC Social, Genetic and Developmental Psychiatry Center at King’s College London. He answered the question about whether or not DNA tests can predict intelligence in an article by the Scientific American titled “Is Intelligence Hereditary,” in which he makes the following statement:
Scientists have investigated this question for more than a century, and the answer is clear: the differences between people on intelligence tests are substantially the result of genetic differences.
One example of mental capabilities tied to genetics is found in idiot savants or people afflicted with Fragile X syndrome, a topic we discussed in our recent article on When Will There be a Cure for Autism? The mental capabilities of these unique individuals can be attributed to their DNA, not what their parents or teachers taught them.
One reason the “genetic testing for intelligence” topic makes some people uncomfortable is that many don’t want to know if they might have drawn the short straw when it comes to the genetic lottery of intelligence. But, let’s be realistic here. Is there any single person out there who would take a genetic test for intelligence and disagree if it incorrectly reported that they were brilliant? Conversely, would they quietly agree with the outcome of the test if it said they were not so bright? You can probably guess the answer to those questions. If that’s the case, then why not just sell a DNA test that tells everyone they’re a genius? That would probably go over well in America, but not in China.
The discoveries mean we can now read the DNA of a young child and get a notion of how intelligent he or she will be, says Plomin, … [who] outlined the DNA IQ test scenario in January in a paper titled “The New Genetics of Intelligence,” making a case that parents will use direct-to-consumer tests to predict kids’ mental abilities and make schooling choices, a concept he calls precision education.
DNA Tests to Predict Intelligence Today
Right now, there are at least a few test providers who offer DNA tests that are associated with intelligence. The key word here is “associated.”
One Belgian company called GenePlaza is trying to emulate the Helix business model by having you upload your DNA information (or take their own DNA test) after which you can access apps like this one:
So, for $6.89 they will tell you how you compare to the other people that shelled out $6.89 for the test. (The fact that they need to tell the reader that the sample shown on their website is actually a sample implies that if you take the test, you may be a big fish swimming in a little pond.) Intelligent people would just pass after reading the disclaimer that says that “for most people, these Single Nucleotide Polymorphisms (SNPs) do not influence their intelligence in any particular direction” and for those that it does, they have a “minuscule” effect on IQ.
Then there’s a test from a U.S. non-profit called DNA Land which also provides you with a bell curve that’s based on the same 2017 study that the previous company uses. There’s an article published in the Atlantic titled “Genetic Intelligence Tests Are Next to Worthless” which described how science writer Carl Zimmer took the test and landed just left of center.
He then contacted Yaniv Erlich, the scientist who wrote the intelligence program, who said he also fell just left of center, and that “Everything is cool. Many smart people end up there” and admitted he wrote the test just to “make people cautious about the connection between genes and intelligence.” They both had a good chuckle about how clever an idea that was, and went on their merry ways. Again, not the sort of test that anyone intelligent ought to consider taking.
To Fix or Not to Fix
Going back to the article we wrote last year about genetic editing at the germline, it seems that most people oppose the idea of choosing embryos that are highly intelligent. According to a survey by MIT Technology Review, half of the people think genetic modification of babies is just fine for serious diseases while 83% think that making the baby more intelligent is going too far.
So what about someone who has an extremely low IQ, like a person with Fragile X syndrome? Where do we draw the line exactly?
Someone once speculated that when the ability to advance human intelligence arrives, there will be two camps. Camp One will adopt the technology and Camp Two won’t. Then, because the intelligence increases will lead to more intelligence increases and intelligence will grow so exponentially, Camp One will grow so monstrously intelligent that they’ll throw all the Camp Two people into large zoos and just view them as a form of amusement, kind of like how we keep pets today.
The point is, if even a small minority choose to advance human intelligence using technology, there are going to be some societal problems that will arise as a result. We already have DNA testing for dating, so it’s not a far stretch to think that some people would demand a similar level of intelligence as their own from the person they decide to procreate with. (It’s funny how everyone who drives a car today complains that everyone else on the road is a “stupid moron,” but as soon as you start to suggest that just maybe “stupid morons” shouldn’t be allowed to procreate, people start vehemently objecting to the idea.)