Most of the improvement in life expectancy in the last 10,000 years has taken place in the last 100 years.
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.