New Issue: Orbital Catastrophe Ahead? Read Now

Peaking Intelligence

Join Our Community of Science Lovers!


On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.


Braininess in kids may not depend on the amount of gray matter so much as how fast it both thickens and thins as they grow up. Researchers at the National Institute of Mental Health and at McGill University used magnetic resonance imaging to scan the brains of 307 children from ages five to 19. They focused on the cerebral cortex, or gray matter, which is responsible for higher thinking. In kids who scored highest on the most commonly used IQ tests, the cortex was actually relatively thinner in early childhood, thickening rapidly between ages seven to 11, and peaking later than in their average-IQ peers. The delayed growth perhaps reflects a longer developmental window for high-level thinking circuitry. The cortex of the smart children also thins faster during the late teens, which could reflect withering of unused neural connections as the brain streamlines its operations. Scan the March 30 Nature for more details.

Charles Q. Choi is a frequent contributor to Scientific American. His work has also appeared in The New York Times, Science, Nature, Wired, and LiveScience, among others. In his spare time, he has traveled to all seven continents.

More by Charles Q. Choi
Scientific American Magazine Vol 294 Issue 6This article was published with the title “Peaking Intelligence” in Scientific American Magazine Vol. 294 No. 6 (), p. 27
doi:10.1038/scientificamerican0606-27b

Subscribe to Support Independent Journalism

Great science journalism requires human expertise, time, effort and creativity. And it costs money. That’s why I and the journalists here at Scientific American hope you’ll join our community.

When you subscribe, you are supporting staff and freelance journalists who are passionate about telling science stories that are true, important and compelling. Our editors and reporters are often experts in their fields, which means they understand the nuances of big discoveries and can untangle the breakthroughs from the hype. With a subscription, you are also supporting rigorous fact-checking to ensure the words we publish are precise and accurate. And you’re supporting original illustrations, graphics and photos that bring you closer to an advanced laboratory, an ice sheet in Antarctica or a space mission in orbit. You’re helping us craft other types of high-quality journalism as well: Our newsletters are carefully written, edited and curated by staffers you have or will come to know and love. Our Science Quickly podcast is based on original reporting, collaboration with editors and scientists and exacting production.

Subscriptions keep this engine running so we can continue to deliver thoughtful, rigorous and independent science journalism to you. In an era of viral misinformation, this work is crucial. If you value what we do, I hope you’ll consider joining us as a subscriber

Thank you,

Jeanna Bryner, Editor in Chief, Scientific American

Subscribe