Inc Magazine
Silicon Valley treats 35 as old but science says that’s nonsense. A Stanford study found cognitive skills peak in the 40s, not 20s. Keeping the brain active prevents decline, with some skills improving into the 60s. Age discrimination in tech isn’t just unfair—it’s flat-out wrong.
When Does Intelligence Peak? A New Stanford Study Offers a Surprising (and Encouraging) Answer
Author: Jessica Stillman
In the tech industry, 35 is apparently considered ancient. A recent University of Gothenburg study conducted in-depth interviews with tech industry insiders and found that workers over age 35 are widely expected “to have more difficulty processing information and picking up new things.”
Add to this a flood of age discrimination lawsuits and the personal testimony of many older tech employees, and you can’t help but conclude that, in some circles, there’s a widespread belief intelligence peaks in your 20s or early 30s. After that, you might be good for maintenance or management, but your days of innovation and intense cognitive effort are behind you.
This is obviously hugely discouraging for founders or tech workers hoping to stay intellectually vibrant and gainfully employed after they sprout a few gray hairs. But that’s not even the biggest problem with this bias against the no longer young. According to a new Stanford University study published in Science Advances, it is also factually totally bogus.
When cognitive skills actually peaks
Researchers out of the Hoover Institution at Stanford University wanted to know if cognitive skills really do start to decline as early as our 30s. They came up with a clever method to check.
Many previous studies looking at cognitive performance over time analyze the performance of some large group on a particular test. If they find that older folks in the group performed worse, they declare that older people are generally less sharp. But the Stanford team thought there might be a problem with such studies.
Sometimes it’s not being older that makes people perform worse on some measure, it’s their environment or education. In some places, education levels have risen sharply. Older folks might score less well on tests, but they also had many years less schooling. Or take another example. Many American Boomers would do terribly if tested on their tech skills. (Sorry dad, but it’s true.) It’s not because they’re old brains aren’t working as well anymore. It’s that they didn’t have access to a lot of tech for much of their lifetimes.
What ideally you want to get around the problem is to test the same people multiple times at different ages and see if and when their cognitive performance starts to decline. Handily, the researchers found just this sort of data was collected for a big study of German adults. When they compared individuals’ test scores at different ages, what did they find?
“Skills increase substantially into the forties for both literacy and numeracy. Subsequently, average skills decline slightly in literacy and strongly in numeracy,” the researchers write. To put it plainly, overall day-to-day intelligence doesn’t peak until well into your 40s.
Use it or lose it.
That blows a rather massive hole in Silicon Valley’s preference for 20-somethings. But it’s not even the most encouraging conclusion of the study for those of us with a few more candles on our birthday cakes.
The German data also included detailed information on the cognitive skills participants were actively using. Were they taking classes, reading books, doing complex math? That allowed the researchers to dig deeper, examining how behavior affects cognitive decline.
Those with college degrees in white-collar careers who used their skills more than average didn’t see declines at all, the scientists found. Their skills actually modestly increased over the second half of their careers. Participants from all backgrounds saw their cognitive skills hold steady at least up to 65 if they kept them exercised. On the other hand, those who didn’t keep their minds active saw their cognitive skills dip in their 40s.
“Individual behavior dramatically affects the age pattern of cognitive skills,” study author Eric Hanushek told PsyPost. “Those who use literacy or numeracy skills at home or work can lessen if not eliminate neurological patterns of skill decline.”
Basically, science just confirmed the old adage, “use it or lose it.”
More evidence intelligence doesn’t peak young
Whenever I write about an interesting new study result, I offer the same caveat. Science proceeds by argument and new evidence. A single result might be overturned or methodologically unsound. You shouldn’t put too much weight on any individual finding.
But there is some reason to take the message of this particular paper to heart. First, because it’s so encouraging. Believing your brain will inevitably slow down in midlife can’t be good for motivation or healthy aging. It also suggests when your intelligence peaks is within your control. If you keep your mind active and no particular medical issues befall you, there is every reason to expect you can stay sharp throughout your working years.
Just because a result is welcome doesn’t make it right, of course. But it’s also worth noting other recent findings agree that how much you use your brain radically affects how they age. One striking study, for instance, found that simply getting older adults to sign up for a class, improved their performance on tests of memory and attention like they were 30 years younger.
Conclusion: Ageism is dumb.
Scientists will continue to argue about the details of when exactly intelligence peaks and how much control you have over brain aging. But it’s already pretty clear that, besides being illegal, Silicon Valley ageism is incredibly silly.
Whatever science finally lands on how the peak of our cognitive prowess it’s not going to be anything near 25. The latest evidence suggests instead that there is no reason to expect your brain to grow rusty if you keep challenging it.
Credits: TCA, LLC.