You know what I like? I like Big Optimism.
If you’re reading this I’m going to assume you’re familiar with it. It’s the once-a-week feature when I write about things like ...
The day in 1926 when John Logie Baird demonstrated television for the first time, and nobody understood what they were seeing.
Or the day in 1960 when Herb Brooks was cut from the U.S. Olympic men’s hockey team, forging his desire to lead the team to victory in the 1980 Olympics, as the coach (the Miracle on Ice).
Or the day in 1968 when Army helicopter pilot Hugh Thompson Sr. almost single-handedly stopped the My Lai massacre in Vietnam.
I try to find things that were momentous or positive or both — but that people didn’t notice on the day they happened.
I like the idea that this is going on all around us all of the time, only we never know how important they are until later.
At this point I have a years-long archive of Big Optimism moments. I can point to almost any date on the calendar and tell you two or three amazing things that happened on that day in history that nobody recognized as important at the time.
In fact, if I ever get a few free days, I’d like turn it all into a book or some other kind of feature.
15% better outcomes
For now, however, I’d like to tell you about a new study out of Harvard University that says making this kind of focused effort to bring more optimism into your life can make your brain a lot healthier as you get older.
A new paper from Harvard T.H. Chan School of Public Health, published in the Journal of the American Geriatrics Society, tracked more than 9,000 cognitively healthy older adults for up to 14 years using data from the Health and Retirement Study, a nationally representative sample of U.S. adults.
Every four years, participants completed a validated assessment of their dispositional optimism — essentially, the general expectation that things will go reasonably well.
The finding? Every one-standard-deviation increase in optimism was associated with a 15% lower risk of developing dementia, even after controlling for age, sex, education, depression, and major health conditions.
Lead author Säde Stenlund explained that a one-standard-deviation difference is roughly the gap between someone with average optimism and someone who is noticeably more optimistic than average.
Yeah, I know, ‘reverse causation’
Now, there’s a natural pushback on a finding like this — reverse causation.
Maybe people who are beginning to decline cognitively become more pessimistic, rather than pessimism driving decline.
Caveat to that caveat, however: Everyone in the study was cognitively healthy at baseline.
Also, the protective effect held up when the researchers excluded the first two years of follow-up — a standard technique for testing reverse causation — and held across multiple sensitivity analyses.
Optimists also tend to manage stress better, exercise more, sleep better, stay socially connected, and seek out cognitive engagement — all things that independently seem to protect brain health over time.
Or maybe optimism itself isn’t doing the protective work directly. Maybe a sunnier baseline disposition simply builds a cluster of habits that together protect the brain. But in a way that’s a distinction without a difference.
That matters because prior research consistently suggests that only about 25% of a person’s optimism level is genetic. The rest is shaped by environment and habit, so maybe make an effort if you don’t do so automatically.
April 8, 2026
Stenlund’s own recommendation was straightforward: Take a moment each day to write down three things you’re grateful for.
That’s probably a bit easier than scouring the annals of history every day to find fun and obscure moments that foretold positivity, but I enjoy it. Honestly, it grew out of me trying to find ways to be more optimistic and thoughtful without any intention of turning it into a newsletter — or knowing anything more than the average guy about brain health.
The journal article was published April 8.
That means a group of Harvard researchers were basically writing today’s newsletter for me that day, and I had no idea at the time.
See? A fun meta-Big Optimism moment on which to end this newsletter!
Other things worth knowing …
AP: Xi Jinping and Vladimir Putin met in Beijing Wednesday — just days after Xi hosted Trump — signing more than 40 cooperation agreements and declaring their countries' ties had reached "the highest level in history." In a joint statement, the two warned against a global return to "the law of the jungle" and took aim at Trump's $175 billion "Golden Dome" missile defense plan.
NPR: Two Chinese tankers exited the Strait of Hormuz on Wednesday carrying 4 million barrels of Iraqi crude oil — the first significant oil movement through the strait since the current standoff began, and a sign that some traffic may be resuming even without a formal deal.
NBC News: A retired Tennessee police officer who spent 37 days in jail — unable to pay a $2 million bond — after refusing to take down Facebook memes about Charlie Kirk’s assassination has settled his lawsuit against Perry County for $835,000. During his incarceration, Larry Bushart lost his job, missed his wedding anniversary, and missed the birth of his granddaughter.
NPR: Rep. Thomas Massie of Kentucky lost his primary Tuesday to Trump-backed Navy SEAL Ed Gallrein, in the most expensive House primary in American history. Massie, who has represented his district since 2012, pushed for the release of the Epstein files, voted against Trump's tax bill, and criticized the Iran war.
Reuters: Cuba’s energy minister announced that the country has completely run out of diesel and fuel oil amid a U.S. blockade. “We have absolutely no fuel, and absolutely no diesel. We have no reserves,” he said on state media, as rolling blackouts lasting 20 to 22 hours a day hit Havana neighborhoods and protests broke out in the capital.
NPR: A federal jury in Oakland took less than two hours to reject Elon Musk’s lawsuit against OpenAI and Sam Altman, finding that Musk had waited too long to file it. Musk had sought up to $134 billion in damages and Altman’s removal, arguing OpenAI had abandoned its nonprofit founding mission. “I can sum it up in one word: appeal,” Musk’s attorney said outside the courthouse.
Billboard: FIFA announced this week that Madonna, Shakira, and BTS will headline the first-ever halftime show in World Cup Final history, at MetLife Stadium in New Jersey on July 19 — curated by Coldplay's Chris Martin and produced by Global Citizen. The show will clock in at 11 minutes.
Thanks for reading. I wrote about some of this at Inc.com. See you in the comments.