Why Past Life Expectancy Numbers Are Misleading

The risks were not uniform

Grant Piper
5 min readAug 12, 2022


(Public domain)

The Roman Empire was the pinnacle of human civilization in the ancient world. They built roads across Europe, developed large and fast-flowing aqueducts, and planted their standard from Spain to Persia. People still travel by the millions to look upon their architecture with their own eyes and marvel at the things that human hands built millennia ago.

But the life expectancy in ancient Rome was a paltry 25 years old. That doesn’t sound grand at all.

Life expectancy during the Medieval Period hovered around 35 years of age. Even at the start of the 20th century, life expectancy was just 50 years old in many so-called developed nations.

Numbers like this evoke images of desolate wastelands where there are no elderly people. Where a village would have one fortunate soul that managed to live into their 50s. That is not the case at all.

In fact, a good number of people lived well into their 60s and 70s in the ancient world and the Medieval world.

The low life expectancy numbers are due to a quirk of statistics that do not paint a full picture.

Statistical Quirks

Life expectancy is a simple average that takes the ages of the deceased, adds them up, and then divides them. This can lead to some strange anomalies that people run with.

Take, for example, a mother who has four children. One child tragically dies shortly after birth. Another child lives to be 21 before dying in an unfortunate car accident. The last two children live to the ripe old ages of 81 and 99. The average life expectancy for this family is 50 years old despite the fact that none of the four children lived anywhere close to 50 years old. It is simply the average of all of their lives.

Take another example. Another mother has four children, except for this time, only one child dies in infancy, and the rest live to the average life expectancy of 80 years old. The life expectancy for this family is 60. That is despite the fact that 75% of the children lived 33% longer than their family’s supposed life expectancy.



Grant Piper

Thought provoking articles, when time and payouts permit it.