If someone tells you the secret to a long and healthy life isn't in your cholesterol, or your waistline, or your salary - but in who you can call at three in the morning - you'll probably think they're overdoing it. And yet that is exactly the conclusion reached by one of the longest studies of human happiness ever conducted.

It is the Harvard Study of Adult Development, launched all the way back in 1938. For nearly nine decades, scientists tracked hundreds of people and their families across several generations - what they ate, how they worked, how much they earned, what they fell ill from, what habits they had. And in the end, the factor that most strongly predicted longevity and well-being was none of those - but how supported a person felt by the people around them.

Robert Waldinger, a Harvard psychiatrist and the study's current director, puts it without any hedging: „Good relationships make us happier, healthier and help us live longer." Not money. Not the gym. Relationships.

The science behind this is entirely concrete. When a person feels supported, the body produces less cortisol - the stress hormone - and more oxytocin and dopamine, which are tied to a sense of safety and contentment. In other words, closeness literally calms the body from the inside.

There is one more detail worth attention: it isn't the number of friends, but their quality. A study at the University of Arkansas found that genuinely close friendships - the ones where you can call at any hour - raised self-confidence and reduced loneliness far more than dozens of shallow acquaintances. A phone full of contacts means nothing if not one of them is there when it counts.

And here is the Balkan part of the story, the one we don't need a study to prove. Around here, the neighbour who brings you a tray of food when you're sick, the cousin who shows up uninvited, the coffee that lasts three hours - that is capital others are only discovering now, in the lab. The question isn't whether we have it. The question is whether, in the race after everything else, we'll hold on to it.

Waldinger adds one more important warning. Research at the University of Oregon showed that relationships that exist only through a screen cannot replace the effect of live, face-to-face contact. Closeness takes time, presence and shared experiences - things you can't download like an app.