Why Some 65 Year Olds Get Mentally Sharper With Age, Not Slower

Dow tops 54,000 for the first time, S&P hits a fresh record as Middle East tensions ease and earnings roll in.

The quick scan: Tuesday was Wall Street's second straight record session. Hopes that the US and Iran can reach a deal to reopen the Strait of Hormuz pushed oil sharply lower, and strong earnings from Palantir and Caterpillar added fuel. All three major indexes closed higher, tech led, and the Dow crossed 54,000 for the first time in its history.

S&P 500: +1.79% to 7,736.52 – closed at a record high, its first in two months, surpassing the previous peak set in early June
Dow Jones: +1.71% to 54,085.88 – rose more than 900 points, a second straight all-time closing high after crossing 53,000 on Monday
NASDAQ: +2.59% to 26,584.99 – led the three indexes, driven by a 29% surge in Palantir on strong quarterly results; still about 2% below its own June record.

What's driving it: Oil fell roughly 5% on optimism that mediators can broker a deal averting US strikes on Iran and reopening the Strait of Hormuz, easing the inflation and growth fears that have weighed on markets since the conflict began. Earnings did the rest. Palantir's outlook reassured investors that AI demand remains intact, and Caterpillar's results boosted industrials. SpaceX and AMD reported after the bell, with AMD slipping in after-hours trading despite solid numbers.

Bottom line: Two straight record closes on the back of de-escalation and strong earnings is a reminder of how quickly sentiment can turn when the macro overhang lifts. For L-Plate Retirees, the lesson isn't to chase Tuesday's rally. It's that markets that looked shaky in July are already back at records, which is exactly the pattern long-term holders should expect and short-term traders keep getting caught out by.

What If Growing Older Actually Made You Sharper?

The scoop: If you asked most 65 year olds whether their memory or their walking speed would improve over the next decade, most would probably laugh. A new study out of Yale says nearly half of them would be wrong to laugh.

Researchers Becca Levy and Martin Slade tracked more than 11,000 people aged 65 and older for 12 years, using data from the US Health and Retirement Study. Every few years, participants sat through a standard cognitive assessment and had their walking speed measured. This wasn't a wellness survey. It was the same kind of testing a doctor uses to flag early decline.

The expectation, built into how we talk about ageing, is a slow one way slide. Memory softens. Steps shorten. You manage the decline, you don't reverse it.

The forty five percent nobody expected.

Forty five percent of participants improved in cognitive function, physical function, or both, over the 12 year window. About 32 percent improved cognitively. About 28 percent improved physically. Many of these gains were large enough to matter clinically, not just statistically. Count the people who simply held steady instead of declining, and more than half of this group avoided the drop in cognitive function that ageing is supposed to guarantee.

Improvement wasn't limited to people starting from an unusually low baseline either. It showed up even among participants who tested as cognitively normal at the start. This wasn't a story about people recovering from something. It was a story about people who kept getting better at something they were already doing fine.

The belief that predicted who improved.

Here's where the study earns its place in this newsletter rather than a medical journal nobody reads.

The strongest predictor of who improved wasn't education, income, chronic disease status or depression, all of which the researchers controlled for. It was how positively a person viewed ageing at the start of the study. People who held more positive beliefs about growing older, at baseline, were significantly more likely to improve on both memory and walking speed over the following 12 years.

This builds on Levy's earlier work on what she calls stereotype embodiment theory: the idea that the cultural stories we absorb about what it means to be old don't stay abstract. They shape how our bodies and minds actually behave, partly through stress physiology, partly through the small daily choices, walking a bit further, taking the stairs, engaging with a hard crossword, that a person makes when they believe those choices are still worth making.

Someone who has quietly absorbed the message that decline is inevitable has less reason to make the effort that keeps decline at bay. Someone who expects to still be sharp at 80 behaves, in small consistent ways, like someone who will be.

What makes this finding harder to wave off is the rigour around it. Levy and Slade weren't comparing optimists to pessimists in a vacuum. They adjusted for age, sex, education, chronic disease status, depression and length of follow up, and the relationship between age beliefs and improvement still held. That's a meaningfully wider net than the kind of finding that evaporates the moment you control for the obvious confounders. It doesn't prove causation, the researchers are careful not to claim that, but it rules out several of the easiest alternative explanations.

This is not a positive thinking cure.

It would be easy to flatten this into "think young, stay young," and that reading does the research a disservice.

This was an observational study, not a controlled trial. Levy and Slade can show that positive age beliefs and improvement travelled together, even after adjusting for age, sex, education, chronic disease and depression. They cannot prove that changing a belief, on its own, changes an outcome. Genuine cause and effect in either direction, or a shared underlying factor driving both, remains on the table.

It also isn't a claim that optimism prevents illness. Plenty of people with strongly positive outlooks still get sick, still decline, still face the biology everyone eventually faces. What the study points to is narrower and, honestly, more useful: how you expect ageing to go appears to shape the daily behaviours that influence how it actually goes, on average, across a very large group of people.

The reversibility nobody tells you about.

The more striking implication may be the one buried under the headline finding. We are handed, almost from childhood, a mental model of ageing as a one way hill. Up through midlife, then down, with the only real choice being how slowly you slide.

This dataset doesn't support that model. Cognitive and physical function moved in both directions, for large numbers of people, over more than a decade. Decline was common, and it remained the more frequent outcome overall. But it was not universal, and it was not fixed once it started. Improvement, real and clinically meaningful, was a live possibility for a substantial share of people already in their mid sixties and beyond.

For a newsletter aimed at people standing at exactly this threshold, that reframing matters more than any single statistic in the paper. The real question isn't whether you'll experience some decline, most people will, in some domain, eventually. It's whether the story you're currently telling yourself about what's coming is quietly shaping which side of that 45 percent, or the 55 percent who held steady or declined, you end up on.

Actionable takeaways for L-Plate Retirees:

• Notice the script you've inherited about ageing. Much of what we believe about growing old was absorbed decades before we got there, from parents, media and offhand comments, not from evidence. Levy's research suggests that script has real behavioural consequences. Worth examining rather than accepting on autopilot.

• Treat "use it or lose it" as literal, not motivational poster filler. The study didn't measure beliefs in isolation. It measured beliefs alongside behaviour over 12 years. A crossword, a walk, a hard conversation, a new skill, these are the small daily bets a person makes when they still expect the effort to pay off.

• Don't wait for a diagnosis to take stock. Improvement in this study wasn't limited to people recovering from a low point. It included people who tested as cognitively normal and got measurably better. The window for this isn't only open once something has gone wrong.

• Hold the finding at the right size. This is association, not proof of a cure, and it's one large US dataset, not a global guarantee. Don't let a single study talk you out of seeing a doctor about a real symptom, and don't let it talk you into believing attitude alone will carry you through serious illness.

• Watch your own language about ageing, out loud. The offhand things we say, "senior moment," "too old for that now," aren't neutral. They're small rehearsals of the very script this study suggests shapes outcomes. Changing the joke doesn't fix everything. It's still worth changing.

Your Turn: 
What is one belief about ageing you inherited without ever examining it, and where did it actually come from? 
Can you name a moment in the last year where you caught yourself acting "old" before your body actually forced the issue? 
If you genuinely expected to be sharper at 75 than you are now, what would you start doing differently this week?

👉 Hit reply and share your thoughts – your answers could inspire fellow readers in future issues.

If today's issue made you rethink what "inevitable decline" actually means, consider shouting L-Plate Retiree a coffee on Ko-fi. Your support keeps this kind of ageing research in front of readers who can use it.