Try “sustained movement and activity levels due to human-scale urban environment”

The calle de jordán, a short street in central Madrid, encompasses the entire cycle of human life. On one block is a fertility clinic, an increasingly common sight in a country obsessed by its shortage of babies. A block further down is a day centre for pensioners, advertising services like memory training and help with mobility. It is common to see women in their 60s gently leading their 90-something mothers up to the door.

But a geographic cluster of relatively poorer countries are also conducive to longer lives: Spain, Italy, France and Portugal. (Three nearby microstates, San Marino, Malta and Andorra, make the top 20, too.) The oldest person alive is a Spanish woman, Maria Branyas Morera (117), who succeeded a French one. Health and long life correlate unsurprisingly with gdp per capita. Why does southern Europe outperform the usual link between wealth and health, making the average lifespan in Spain (85.5 years in 2050) longer than that of the average Dane (83.5)?

Many point to the “Mediterranean diet”—fish, whole grains, fresh fruit, vegetables and olive oil. Critics, though, point out that diets differ widely from Portugal to Greece. Besides, researchers find that today’s Mediterraneans do not stick to their namesake diet. Plazas in Spain are full of people eating fried fish and salted ham, washed down with beer at hours some might consider unseemly. Spaniards drink more booze and smoke slightly more than the European average, and are among Europe’s biggest cocaine users.

Dan Buettner, who has written several books on areas where people live long, notes that to understand why people grow old one must look not at today’s habits but at those of half a century ago, when people ate “peasant food”, dominated by grains, beans and tubers. A recent study of the “blue zone” (a designation for areas that feature many centenarians) in Sardinia found that the diet included “famine foods”, such as bread made from acorns and clay and a cheese made with insect larvae. The most notable fish product was salted, dried mullet ovaries; inland shepherds rarely ate fresh fish. Diets today increasingly include Western processed foods, but “cultural inertia” keeps them somewhat healthier, says Mr Buettner.

The Institute for Health Metrics and Evaluation at the University of Washington recently issued projections for longevity by country in 2050. Among the top 20 for living to a ripe old age are rich ones like Switzerland and Singapore. East Asia is also represented by South Korea and Japan, longtime longevity leaders. That shepherding past points to another factor: movement. Spaniards lead western Europe in steps per day at 5,936, according to a study from 2017. (Italy, France and Portugal are less impressive.) The study found that countries with “activity inequality”—a few prolific walkers but many couch potatoes, as in America and Saudi Arabia—had the highest obesity rates. Those where everyone moved a reasonable amount, as in Spain, had low ones. That evidently reduced mortality from obesity-related diseases.

Why do Spaniards move so much? Spanish cities, and even tiny pueblos, are densely populated; hit the city limits and you are often in empty countryside. Neither culture nor regulation favour sprawling suburbs, so even with abundant land, Spaniards live on top of each other. Paris and other places aiming to create “15-minute cities”, where most necessities are within walking radius, could learn much from Spain. The same study that looked at “activity inequality” examined urban America, finding that dense cities like New York and Boston had greater (and more evenly distributed) levels of activity than sprawling places like Atlanta and Phoenix.

But stressing diet and exercise misses a piece of the puzzle. Spain’s walkability is also good for social life. Cities are built around plazas where friends, family and co-workers sit, eat, drink and talk. That turns out to be good for you even if you sip vermouth and eat crisps at noon. Reams of research show that social contact is critical for physical and psychological well-being.

According to a recent survey by Gallup, a pollster, and Meta, a social-media company, 76% of Spaniards say they feel “very” or “fairly” socially supported. That is above average, though not top of the table. Jon Clifton, head of Gallup, says his firm’s research shows that Spaniards are fairly unhappy and disengaged at work. He quips that a headline in El País, a newspaper, got it more or less right: Spain is “the best country to live in and the worst to work in”. But work is not everything. Spaniards are fourth in the world when asked whether they have seen friends or family who live near or with them in the past week (Greece was second). This may be the unexpected upside of the fact that many young southern Europeans cannot get good enough jobs to afford to move out of their parents’ homes. Family bonds remain tight, including in trying times like the financial crisis and the pandemic.

Southern European countries do not score highest on happiness—that title has long been held by Denmark and Finland. But happiness assessments weight long-term life satisfaction more heavily than short-term smiling and laughing. Those sorts of gleeful emotions are reported most often by Latin Americans. And, metaphorically and physically, a line drawn from Helsinki to Buenos Aires would pass through Spain. That country has European levels of wealth (the best predictor of happiness) and health care (which keeps people alive), while also sharing cultural traits with Latin Americans: living for the moment and treasuring friendships and families. These are not just good in themselves. They keep you going, too.