Chapter Content
Okay, so, let's talk about this idea that we inevitably decline as we get older, especially when it comes to our brains. You know, people always say things like, "Oh, you can't teach an old dog new tricks," or that, you know, your memory goes to pot after a certain age. But is that really true? I mean, that's what we're gonna kind of delve into here.
There's this whole, like, narrative out there, perpetuated, you know, a little bit by some experts, that your prime is over, like, way sooner than you think, and that cognitive decline is just, like, inevitable. But, like, is that really the whole story?
Turns out, there's a bit more to it. There's this idea of fluid versus crystallized intelligence. Fluid intelligence is, like, your raw processing power, your ability to, you know, think on your feet, solve new problems. Crystallized intelligence, on the other hand, that's your accumulated knowledge, your vocabulary, all the stuff you've learned over the years. And while, yeah, fluid intelligence might dip a little earlier in life, crystallized intelligence? That actually keeps getting stronger for, like, way longer. Which is kind of cool, right?
You know, you might hear people complaining that their memory isn't what it used to be, or that they can't think as fast, and that *is* true for some people in some respects. But that doesn't mean your overall intelligence is just, like, plummeting.
And it's interesting, there was this neurologist, George Bartzokis, who looked at the structure of the brain and how it changes as we age. He found that we actually gain more myelin, which is, like, the insulation on our nerves, in the parts of our brain responsible for, like, memory, decision-making, language, emotion, all that good stuff. So, while our processing speed might slow down a tad, we're actually better able to, you know, *use* all the information we've got stored up there. It's like, as Bartzokis put it, that's basically what wisdom *is*. It's kinda neat, right?
So, how does all that knowledge actually play out? Think of it like this: your brain is like the internet, you know? You've got all these different clusters of information, like, everything you know about your job, everything you know about your hobbies, and they're all connected, but not always super well-connected.
And moments of insight, those "aha!" moments, they happen when you suddenly link up these different clusters. The bigger your knowledge base, the more you benefit. So, connecting two tiny little clusters isn’t gonna get you very far, but connecting two, like, huge, well-developed clusters? That's where the magic happens.
So, the key is to actively explore those different areas of expertise, connect all those dots. I mean, you could even take a more active role, like using Brian Eno's "Oblique Strategies" cards to kinda nudge yourself into new ways of thinking.
Honestly, it's really about *how* you use your intelligence, not just how *much* you have, you know? Don't buy into that whole, "I'm too old to learn this" thing.
There was this really fascinating study. So they gave people the same IQ test they took when they were kids – like, decades later. What they wanted to know was: do the people who scored high as kids, still score high as adults? And you know what? There was huge variation! Some people did way better later in life, some did worse. It wasn't set in stone.
What makes the difference? Well, there's a lot of debate about genetics versus environment. Seems like childhood intelligence only accounts for about half of the differences in scores later in life. The other half? That's up for grabs.
Things like stimulating environments, intellectually challenging activities, exercise, good diet, they all seem to play a role in preserving cognitive function. It's all, like, a package deal, you know? Healthy body, healthy mind. Sleeping well, exercising, not smoking, eating right… It all adds up.
Think about SuperAgers, these people in their eighties who have the brain function of someone 20 years younger. They tend to be social, mentally active, and take care of themselves physically. So, like, you know, that really adds to the "use it or lose it" type of mentality.
What about different types of intelligence? Well, raw speed might peak early, like in your teens, but things like recognizing faces improve until your 30s. And your ability to evaluate other people’s emotions? That can peak in your 40s or 50s. And vocabulary? That can keep growing into your 60s and 70s.
The thing is, there is really no age when humans are performing at their peak on *all* cognitive tasks. So, let's ditch the idea of this simple decline, and think of it as a shifting landscape, where different abilities come to the forefront at different times.
I mean, you know, caution starts to increase in our early twenties, so some people, like, think the only way to move forward is to be a little bit reckless! Being a little bit reckless can be a *good* thing!
Another thing to think about is, what do we *mean* by intelligence anyway? IQ is important, sure, but it's not the whole picture. There's also sociability, emotional intelligence, the ability to manage complex relationships. And these things become even more valuable as we age.
Ultimately, it's about attitude, circumstances, and personality factors. It's not just about raw brainpower, it's about motivation, perseverance, curiosity, openness.
So, what's the takeaway here? Don't let those graphs of average decline scare you. They're just averages! We should see ourselves as adaptable. Changing our focus, our environment, our collaborators, what we work on, it can all make a huge difference, no matter our age.
There's this idea, it's called the "constant probability of success" theory. Basically, it says the more attempts you make at something, the more chances you have of succeeding, regardless of your age or stage in your career. People who keep trying have more successes! It really is that simple!
There's this other thing, it's called the "ten thousand hour rule", popularized by Malcolm Gladwell. Basically, that it takes ten thousand hours to become amazing in any discipline. The idea is, it takes a decade of deliberate practice to achieve mastery in a given discipline.
But, even the guy who came up with the research behind the ten-thousand hour rule says it's not as specific as it sounds. What matters is accumulated expertise, not your starting point. A recent sociological study found that, as authors get older, their work changes less, but then there are also, like, tons of authors who just keep changing all the way until the end.
Scientists tend to do their most significant work young because they're more productive, but that's not to say, "Oh, it's never gonna happen after that." Like, John B. Fenn won the Nobel Prize in Chemistry for a paper he published *after* he was forcibly retired!
So, again, the "equal-odds rule" states that each work a scientist or artist produces has the same statistical chance of being great as any other work. You'll do your most significant work in the period when you do your most work. If you do what you want, when you want to do it, you have just as much a chance to succeed!
There's this thing called the Q factor. You need perseverance, luck, but also, you need to get people to notice you. Q is about communication skills, education, likeability, motivation, openness to ideas, and collaboration. The Q factor is independent of each other.
Back to the youth and age thing: We see all these stories that great mathematicians have to be young, but, I mean, you hear about Einstein making these theories as, like, a young prodigy, but we tend to forget that Copernicus didn't finish his theory of planetary motion until he was 60.
Now, before 1905, prize-winning work was done before 40, like, a lot, but after the twentieth century, it basically didn't happen. I think a lot of the time, this has to do with education, and that scientists spend more time in graduate school as the accumulated burden of knowledge required more study.
There are experimental thinkers and conceptual thinkers. experimental thinkers work incrementally, and conceptual thinkers require less learning. Galenson did a study where he looked at economists and determined that the economists with the most conceptual ideas did their important work twenty years earlier than the most experimental thinkers. There are also some scientists who made great discoveries because their knowledge of some classical electromagnetism was so poor, they nearly failed his PhD.
From 1964 to 2014, two-thirds of Nobel Prize-winning scientific research was done in the United States, which had 5% of the world's population. As the authors of the Kellogg study said, "Age and scientific genius are empirically characterized by great variation across individuals and over time."
The Fields Medal is the most prestigious maths prize, but it is always awarded to a mathematician aged 40 or under. I mean, a committee member literally suggested a cut off of age 42 because the guy he didn't want to get the medal was 43 the previous year.
But there is no connection between age and declining productivity in maths. Sociologist Nancy Stern did a paper about this, and she concluded that "There is no apparent overall relationship between age and mathematical productivity."
Basically, productivity can be maintained, but only if steps are taken to compensate for declining energy, memory, and computational ability. It sounds a little downbeat, but it is far more optimistic than, like, some of the old sayings. And when we consider that the latest research says that we don't lose mental speed until much later than previously thought, it becomes even more optimistic. You could even bring a younger collaborator!
Then there's Yitang Zhang. He submitted a paper to the Annals of Mathematics, but nobody knew who he was. The editor had to send it for review by someone who was qualified to look at this complicated problem. They wrote back pretty quickly to say, "If this is correct, it's really fantastic. But you should be careful. This guy posted a paper once, and it was wrong. He never published it, but he didn't take it down, either." So, he wasn't on anyone's radar to say the least.
I mean, here's a guy who was sending papers to the Annals and nobody had ever heard of him, and he basically has a huge role in moving the needle for twin prime conjecture.
He says, "I don't care so much about the age problem. I don't think there is a big difference. I can still do whatever I like to do." The biggest barrier is stopping, and there are various explanations why people stop. They have families, or they have their tenure, or their interests change, but anyone ambitious enough to want to change their lives, or work on big problems, can simply not quit.
He worked on a farm, because his dad had some political problems, and didn't go to school, so he formed the habit of solving problems in his head. He went to Peking University when he was 23. He was the best student in the department. His professor didn't let him study at the University of San Diego.
Moh believes Zhang was not forced to study algebraic geometry in Beijing. "It was possible that what happened was Yitang pretended to be interested in algebraic geometry and fooled Prof Ding to recommend him… Yitang published no paper in Algebraic Geometry. Yitang wasted 7 years of his own life and my time and an opportunity of a young Chinese Algebraic Geometor."
Zhang claims Moh refused to write him a letter of recommendation, without which it was impossible for Zhang to get an academic position. Moh says that when Zhang graduated there was a new system coming into place, the ‘tenure track’, which meant students had to look for jobs on their own.
Moh said, "I was sure of one thing - he could not survive the life of “tenure-track,” “tenure,” and “promotions.” It was not his type. I regarded him as a free spirit, and I should let him fly.” He was part-time calculus teacher at the University of New Hampshire when he was 44. He says, "The important reason is that I persisted for several years. I didn't give up… The most important motivation is to really love mathematics."
The speechwriter and playwright Ronald Miller did much of his best work while sitting on a train, and Noël Coward was forced to spend a week in bed with flu and wrote Private Lives. It's not just cognitive ability that matters. It's about what produces the best ideas. So, go have the flu if that helps. The cognitive ability isn’t enough; it is about using your smarts in a way that produces the best ideas.
Zhang is now 67 and has published a paper claiming to have made progress on another significant problem. He said, "There are a lot of chances in your career, but the important thing is to keep thinking."