Life Expectancy Through the Ages

Contributor: Nathan Murphy. Lesson ID: 13801

Life expectancy has nearly doubled in the past 200 years. Does this mean people are living twice as long? Learn how this metric has more to do with the beginning of life and less with the end.


History, People and Their Environment, World

Social Studies
learning style
Auditory, Visual
personality style
Grade Level
High School (9-12)
Lesson Type
Dig Deeper

Lesson Plan - Get It!

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The Death of Socrates is a 1787 painting depicting when the Greek philosopher Socrates was sentenced to death in 399 B.C.:

The Death of Socrates

Image by Jacques-Louis David, via Wikimedia Commons, is in the public domain.

While the artist made him look youthful, he was 71 years old when he was forced to drink poison.

  • Did you think people could even get that old thousands of years ago?
  • How did he live longer than most other people in his generation?

Let's find out!

Pre-Modern Life

Greek mythology

People like Socrates, who would have lived even longer than 71 years, were not incredibly special during pre-modern times. Athens did not have some special youth potion.

However, up until 1800, there was not a single country with a life expectancy over 40 years of age.

  • How does this make sense?

Look at this graph of the average life expectancies across continents from 1770 to 2018:

life expectancy by world region

Image by Max Roser, via Wikimedia Commons, is licensed under the CC BY 4.0 license.

  • So, what changed?
  • And what did this mean for the inhabitants of each continent?

Infant Mortality Rate

infant mortality

Life expectancy is calculated by finding the average age to which a person can expect to live; however, there is one primary factor that weighs this number down heavily.

The number of babies who die shortly after birth greatly affects the average age of an area.

Watch Nigeria Infant Mortality: In Nasarawa state, 103 out of 1,000 babies die from TRT World:

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In countries without good, accessible healthcare, most babies requiring any medical attention die shortly after birth.

Half a million babies die on the day they are born each year in sub-Saharan Africa simply because they do not have access to doctors in the same way those born in developed countries do.

Because of this high infant mortality, the life expectancy in Nigeria as of 2018 was only 54 years. The availability of modern medicine in most large cities has lifted life expectancy higher than in centuries past, but infants remain highly susceptible to death in their first days of life.


In past centuries, if a person lived to be 10 years old, they would likely live into their 50s and 60s.

Many people were born, and countless passed away as children. However, once becoming teenagers, most went on to live a long life. The major barrier to a long life, in the past, were medical conditions -- especially infectious diseases.

You have undoubtedly heard of the Black Plague, which swept around the world in the 14th century; however, pandemics like this have always existed.

As you watch The Plague of Justinian, from The Pacifist, compare this response to the modern-day COVID-19 response:

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In 2019, the governments of developed countries like the United States and those in Europe were able and willing to prevent as much loss of life as possible. Whether you agree or disagree with the response to COVID-19, it is clear that more people would have died from the disease if the world had done nothing about it, like with past plagues.

Infectious diseases like this were the primary barrier to living into old age as a member of the pre-modern world.

Industrial Age

machinery factory

  • So, what changed?

Beginning in the 1800s, people moved into larger cities. By the 1920s, more Americans lived in urban environments than rural ones.

This led to an increase in American wealth from industrialization, which could be used on hospitals and medical research that would help to not only protect people against disease but also care for infants, thereby preventing as much loss of life as possible.

Because most infants in the United States survive childhood and because most infectious diseases have vaccines, a majority of Americans live into their 60s.

However, the life expectancy in the United States is not 60 or even 70. The life expectancy in the U.S., as of 2018, was 79 years. Check out this Life Expectancy graph, from Data Commons Timelines, to see how this has increased since 1960.

This incredibly high life expectancy is not due to fewer infants dying or stopping pandemics. It is because of medical advances and things like antibiotics.

While most adults could expect to live into their 50s or 60s four hundred years ago, any person born in the U.S. should live an extra 20 years due to advanced medicine.

hospital entrance

  • Now that you understand life expectancy, does it make sense why a person in ancient Greece could have reasonably lived into their 70s even though life expectancy was in the 30s?

Move on to the Got It? section to make sure you understand the factors that go into life expectancy and what it really means.

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