Brain image via Shutterstock
Scientists have long known that our genetic makeup influences our intelligence. But now, thanks to the largest brain study of its kind, they've pinpointed one gene in particular that may be responsible for our IQ levels. Meet HMGA2. You can call it the "Intelligence Gene" — that's what Paul Thompson, professor of neurology at UCLA and the leader of the massive study, has dubbed it.
By looking at the brain scans of more than 20,000 people from North America, Europe and Australia, Thompson and his fellow researchers identified a variant in HMGA2 — a single different molecule in its string of DNA — which influences brain size, adding about 2 teaspoons of brain volume to people who possess it. In a separate analysis in Australia, researchers discovered that subjects who possessed the Intelligent Gene and had larger brains, also scored slightly higher on IQ tests. Translation: This gene variant makes your brain bigger AND it makes your IQ higher.
How much higher?
Roughly 1.30 points. An average IQ is 100. "The effect is small," Thompson admits, but it "may mean you get a couple more questions correct" on an IQ test.
Some complain that the effect is so small, it can't possibly be relevant, especially since it required such a huge population of participants to find. But what the finding lacks in magnitude, it makes up for in impact. For the first time, science has proved that miniscule genetic changes effect our brain power, something many a study has tried and failed to prove in the past.
Is it in you?
So how prevalent is this Intelligence Gene? It showed up in about a quarter of the study's 20,000 participants. Unless you want to undergo some serious brain scans, there's really no way of knowing whether you're one of the lucky ones. And if you aren't, you're not doomed to a life of stupidity.
Researchers are quick to point out that a number of things influence our intelligence level, like a good education, diet and exercise. "Most other ways we know of improving brain function more than outweigh this gene," Thompson says. So go for a run, read a book and eat well. And take comfort in knowing that, as the New York Times says, "some very smart people have relatively small brains."