Common Misconception About Life Expectancy

When we read that life expectancy was 40 years in the early 19th century, we might quickly imagine a miserable human existence in which people are born, struggle through life, and then die at the ripe age of 40. However, it doesn't exactly work this way. While undoubtedly there were some unfortunate individuals whose lives followed that trajectory, life expectancy represents the average lifespan for a group of people, not a prediction for an individual.

For instance, it is estimated that in the early 1800s, 20-30% of children did not survive past the age of five. Therefore, if we consider a group of 100 individuals from that era and 30 of them died by age 5, the other 70 might live to an average age of 55. The high rate of childhood mortality significantly lowers the average life expectancy, whereas surviving childhood could lead to a considerably longer lifespan.

I became fascinated by the question of life expectancy when I read the biographies of some prominent figures of the past. John Adams died at age 90, James Madison at age 85, Benjamin Franklin at age 84, Thomas Jefferson, Voltaire and Victor Hugo at age 83. They were not ordinary citizens, of course, but they had fairly long lives even by today's standards before antibiotics, vaccines, statins, X-rays, and MRIs.

To me, it shows the marvel of human biology. I wholeheartedly support the advances of modern medicine, but it is inspiring to see what our bodies are capable of given some luck and proper care.

P.S. It seems that being President of the United States might be linked to a longer lifespan (unless tragically ended by assassination). Alternatively, perhaps a high level of vitality is required to become President.