Does Wearing Glasses Mean You Are Smarter? Yes, Suggests New Genetic Study

It's a common high school movie trope: the dorky, four-eyed kid who excels academically despite their failing sight. But a new study suggests there might be a kernel of truth in that stereotype.

In what is believed to be the largest genetic study into cognitive function, researchers in Scotland drilled down into data on over 300,000 people in North America, Europe and Australia to identify genes associated with intelligence.

Among their findings was that those with higher levels of intelligence were more likely to need reading glasses than those with lower scores. The authors of the study also found "significant genetic overlap" between other variables such as hypertension and factors including general cognitive function and reaction time. Links were also found between reaction times and conditions such as ADHD, bipolar disorder and schizophrenia.

The team at Edinburgh University arrived at their findings, published in the journal Nature Communications, by combining cognitive and genetic data of participants ages 16 to102 years of age. They investigated 148 genomic regions linked to cognitive function, including 58 that had never been reported before.

Participants' intelligence was rated using the results of cognition tests as well as verbal and numerical reasoning.

Chief Executive Officer of Apple, Steve Jobs attends a press conference in London, on September 18, 2007. A new study has linked wearing glasses to higher levels of intelligence. SHAUN CURRY/AFP/Getty Images

As individuals with higher levels of cognitive function "tend to live longer and be less deprived," the authors noted, associations between intelligence and physical health could offer important insight into how and why our brains can stay healthier for longer.

However, the researchers acknowledged that the association isn't causal, and that measuring intelligence is "far from being standardized."

Gail Davies, of University of Edinburgh's Centre for Cognitive Ageing and Cognitive Epidemiology (CCACE), an author of the study, said in a statement: "The discovery of shared genetic effects on health outcomes and brain structure provides a foundation for exploring the mechanisms by which these differences influence thinking skills throughout a lifetime."

Ian Deary, director of the CCACE and lead author of the study said in a statement: "Less than a decades ago, we were searching for genes related to intelligence with about 3,000 participants, and we found almost nothing. Now, with 100 times that number of participants, and with more than 200 scientists working together, we have discovered almost 150 genetic regions that are related to how clever people are."

Even larger studies are now needed to reveal more of the picture, Deary said.

"We also need to study our results closely to see what they can tell us about the possibility of understanding the declines in cognitive function that happen with illness and in older age. One thing we know from these results is that good thinking skills are a part of good health overall."

Deary told Newsweek: "I am surprised by the long list of health-related traits that show genetic overlaps with performance on cognitive tests. I've been working on human intelligence for years, and it was a long time before I appreciated how health relevant it is; our new study reinforces that appreciation."

Natasha Sigala, an associate professor in neuroscience at the Brighton and Sussex Medical School who was not involved in the research, told Newsweek the associations between reaction times and ADHD, bipolar disorder, and schizophrenia surprised her the most. She also agreed with the authors that there is no standard way to measure cognitive function, and that the results aren't proof of a causal association between a person's physical health and intelligence.

"Genetic studies of cognitive function are in their infancy, but this study is important in its sample size and power to detect novel associations between genes and traits," she said.

"We are trying to map out constellations of genes that work together to create our amazingly complex and adaptive brain. In that sense, this study boldly goes further than anyone has gone before."

Maxine Sherman, a postdoctoral research fellow at the University of Sussex who was not involved in the research, told Newsweek: "We still don't know why they [genes and traits] are associated—what exactly are these genes 'doing,' and how does that lead to short-sightedness on the one hand and high general cognitive function on the other?

"Possibly these genes are involved in a more fundamental or basic trait, which in turn predict both shortsightedness and intelligence."

Updated | This article has been updated to include comments from Natasha Sigala, Professor Ian Deary and Maxine Sherman.