Life expectancy is not spread evenly across the world. Some countries cluster around longer lives, while others begin from a much lower baseline. This opening map sets up the main question of the story: why does the chance of a long life change so much depending on where someone is born?
Income explains part of the pattern. Richer countries often have better food systems, safer housing, cleaner water and stronger health services. But the curve begins to flatten, which shows that after basic needs are met, extra national wealth does not always turn into many more years of life.
Even countries in the same income group do not always achieve the same life expectancy. This spread is important because it shows that money alone is not the full answer. How a country turns its resources into healthcare, prevention, safety and everyday living conditions also matters.
The place people live in also shapes the risks they carry in their bodies. Air pollution is one example of how environment becomes health. Countries with higher PM2.5 exposure often sit lower in the life expectancy pattern, showing that longer life is also connected to the quality of the air people breathe.
The final chart compares actual life expectancy with what GDP alone would predict. Countries above the line are living longer than their income level suggests, while countries below the line are falling short. This shows that the long-life lottery is not only about wealth, but about how well societies convert resources into health.