Overview of Working memory: the surprising decline of dementia
This episode of The Intelligence explores three very different stories: a striking long-term decline in dementia rates in rich countries, Brazil’s controversial-but-popular instant payments system PIX and why it drew fire from the Trump administration, and the unexpected comeback of emo music as a multigenerational cultural phenomenon.
Dementia rates are falling, despite an aging population
The first segment challenges the common assumption that dementia is inevitably becoming more widespread.
Main findings
- Dementia rates have declined substantially over the past few decades in several high-income countries.
- One cited example: between 1988 and 2015, the share of older people with dementia fell by about 13% per decade across six countries in North America and Europe.
- Among people in their late 80s, dementia prevalence fell from roughly 3 in 10 in the 1980s to about 1 in 10 today.
Why this is surprising
- Dementia risk rises sharply with age, so longer lifespans and the baby-boom generation led many analysts to predict a major increase in cases.
- The data suggests that age-adjusted risk is falling, even if the total number of older people is rising.
What may be driving the decline
Researchers still do not fully understand the biological mechanisms, but several modifiable risk factors appear important:
- Better control of high blood pressure and high cholesterol
- Not smoking
- Avoiding obesity
- Treating hearing loss and depression in midlife
- Improved education early in life
Notable medical insight
- The episode highlights the shingles vaccine as a promising, low-cost intervention.
- Natural experiments suggest it may reduce dementia risk by around 20% over seven years.
What hasn’t worked well
- Drugs aimed at removing amyloid/protein tangles in the brain have largely disappointed.
- These treatments offer only modest benefit and can carry risks, especially for people with the APOE4 gene variant.
Key takeaway
- Up to 45% of dementia cases may be preventable or postponable through a mix of lifestyle, medical, and policy interventions.
- The challenge is not only scientific but political: governments tend to underinvest in prevention because the payoff comes later.
Brazil’s PIX: a national success story caught in a trade fight
The second segment looks at Brazil’s instant-payment platform, PIX, and the strange decision by the Trump administration to target it.
What PIX is
- PIX is a free, instant digital payment system created by Brazil’s central bank.
- It works 24/7, often via phone and QR code.
- Around 80% of Brazilians use it, and it now accounts for more than half of all payment transactions in the country.
Why it became so popular
- Before PIX, digital payments often came with fees that pushed many lower-income Brazilians toward cash.
- PIX helped bring about tens of millions of people into the formal financial system.
Why the U.S. objected
- The Trump administration argued that PIX:
- Hurts American payment firms like Visa and Mastercard
- Gives Brazil’s central bank an unfair advantage by operating and regulating the system
Why those claims are weak
- Foreign and domestic financial institutions can connect to PIX on the same terms.
- PIX is not shown to discriminate against U.S. companies.
- The bigger competitor to PIX has been cash, not card networks.
- Card usage has continued to rise alongside PIX.
Bigger implications
- PIX may pressure card companies over time by lowering transaction fees, but that is normal market competition.
- It could serve as a model for other countries, but Brazil’s success depended on unusual conditions:
- a strong, trusted central bank
- a large market
- widespread reliance on cash
- Mexico’s attempt to copy the model largely failed because banks were not compelled to adopt it.
Political effect
- The U.S. attack appears to have backfired.
- PIX has become a symbol of Brazilian pride and resistance to foreign interference.
- The controversy may even help President Lula politically.
Emo is back — and bigger than before
The final segment covers the revival of emo music and how it has become a cross-generational cultural force.
What’s happening
- My Chemical Romance launched a major world tour tied to the 20th anniversary of The Black Parade.
- The band played three sold-out nights at Wembley Stadium, showing huge demand despite not releasing new music since 2008.
Why this matters
- The comeback is part of a broader emo revival, alongside renewed interest in acts like:
- All Time Low
- Jimmy Eat World
- Festivals and reunion tours such as When We Were Young and the return of Warped Tour have helped sustain the trend.
Who’s attending
- The audience spans:
- Millennials (“elder emos”)
- Gen Z, many of whom discovered the bands after their original peak
- Even children attending with parents
Why emo still resonates
- Emo’s appeal lies in its emotional openness, introspective lyrics, and acceptance of outsider identity.
- Fans describe the scene as welcoming to people who are “weird,” queer, neurodivergent, or otherwise outside the mainstream.
Key takeaway
- Emo was never just a phase; its return reflects both nostalgia and the enduring appeal of self-expression and emotional honesty.
Overall takeaways
- Health: Dementia is not an inevitable destiny; prevention and early intervention matter more than many people realize.
- Economics and policy: Brazil’s PIX shows how public digital infrastructure can reshape daily life and trigger geopolitical friction.
- Culture: Emo’s revival demonstrates how “youth” genres can become lasting, intergenerational communities.