Johan Norberg describes the tremendous progress in the last several hundred years in so many areas: life expectancy, health, sanitation, liberty, education, and equality. He discusses these wonderfully delightful trends in his book Progress: 10 Reasons to Look Forward to the Future. I will highlight merely a few of the many things I found fascinating in the book.
Book provides the following estimates of life expectancy, which I graph above:
- 20-30, prehistoric times, I will assume that is about 6000 BC
- 18-25 – ancient Greece and Roman Empire, say 200 BC
- 17-35 – medieval England, say 1300
Growing international trade after that point spread contagious diseases. Text says:
- Smallpox traveled from Europe to the Americas
- Syphilis traveled from the Americas to Europe
- Plague accompanied the Mongol conquest
- Cholera spread on merchant ships out of India
More life expectancies:
- 33 – Western Europe in the 1830s
- 31 – worldwide average life expectancy in 1900; notice the shift from more economically developed Western Europe to a worldwide average
- 71 – worldwide average life expectancy in 2017
I graphed that data, which you can see at the top of this post.
What jumps out from the data is what he says in the text: most of the improvement in life expectancy have taken place in the last 4 generations out of what he says is 8000 generations of humans that have lived. That vast improvement took place in a radically short period of time.