The life expectancy of the world population has changed a lot over the years. When we go way back and look at the pre-modern world, life expectancy was not more than 30 years old in all areas of the world.
In the development of life expectancy, it is significant that until the 19th century it seemed to stay relatively even, between 30 and 40 years. But as from the beginning of the 1800´s the life expectancy started to increase significantly. Consider that in the United Kingdom life expectancy until 1800 had changed little and without consistency, as said it fluctuated between 30 and 40. Between 1800 and 2000 this life expectancy increased from 30/40 to almost 80 years old.
At the beginning of the 19th century life expectancy especially started to increase in the more industrialized countries. This had to do with the relation between a country being rich and living in better health contrary to countries that are poor who remained living in bad health. Eventually, also the life expectancy started to increase in these countries and by now life expectancy has doubled worldwide to an average of 70 years old. No country in the world has a lower life expectancy than the one with the highest life expectancy in 1800.
The last 200 years, people´s life expectancy has gone through a major change. Still, life expectancy in many countries is fairly low. When we look at countries in Europe but also in North America, Australia, and Japan, life expectancy is around 80 years old. China, other American countries, eastern European countries and some northern African countries are rapidly approaching this with a life expectancy between 75 and 80. Russia and some other Asian countries, as well as a few African countries and the rest of the southern American countries, have a life expectancy that is between 65 and 75. There are almost no countries in the world with an expected life expectancy below 65 except for Africa, In Africa, the majority of the countries has a life expectancy below 65 and some even as low as 50 years old.
The effect of child mortality
Since life expectancy is an average, the rate of child mortality highly influences the life expectancy. In a previous time there was a greater mortality rate but also this has decreased over the years. Taken the United Kingdom as an example, a child of 5 years old could expect to become 55 years old in 1841. Nowadays a 5-year-old can expect to become 82 years old. Also, a 50 year old´s life expectancy has increased. A 50 year old in 1941 could expect to live to 70, now at the same age you can expect to become 83 years old. Chances of dying at a younger age have reduced significantly.
Only 50% of babies born in 1850 could expect to live to become 50 years old. At the current day over 95% of babies born can expect to reach that age. More significantly maybe, being born in 1850 meant you only had a 10% chance of becoming 80 years old. Today 85% of babies born can expect to become 80 years old. And predicted for 2030 is that this percentage is even going to rise. 35% of babies born in 2030 can expect to live to become 100 years old! Until 1950, that chance was only slightly more than 5%. Keep in mind these numbers account for the United Kingdom.
The turning point
Thus, for the greater part of the past, life expectancy remained stable, but there was a turning point. Not every part of the world experienced this turning point at the same moment. In Europe, America and Oceania, life expectancy started to increase as from 1870, as the first in the world. Followed by the former Soviet Union and Asia just after 1910 and this turning point did not happen on the continent of Africa until 1925. What these regions did have in common is the enormous rise that happened after that moment. But until today we see that the start of the increase holds relation with the life expectancy as it is today. Europe, America and Oceania have the highest life expectancy followed by the former Soviet Union and Asia and life expectancy in Africa are lowest.
Inequality of life expectancy
When we look at the inequality in life expectancy in the world, there is something that stands out. In 1800 there was little difference in life expectancy between all countries. The lowest life expectancy was 24 years in India and the highest was just under 40 in Belgium. But after that, certain countries started developments and others did not so much. Therefore in 1950, there was great inequality in life expectancy. Mainly European countries and America had greatly developed and the highest life expectancy had risen to 72 in Norway, but the lowest life expectancy in the world was still 24 years old, some countries had minimally or not even gone through developments. Then we look at 2012, and this is what is striking; the countries that were already developed by 1950 only had a small increase in life expectancy, which rose to 84 in Japan, but the lowest life expectancy in the world was now almost 50, in Sierra Leone. 7
In 1800, 50 % of the world population had a life expectancy that did not go over 32, in 1950 this age had risen to only 42, meaning over a time frame of 150 years. In 2012, meaning over a time frame of 62 years, this life expectancy of 50% of the world population had risen to 71!
Life expectancy and health conditions
When looking at the increase in life expectancy it is also interesting to look at the years lived in good health and the years lived with a health condition. There we see that with an increasing life expectancy, the number of years that people live with a health condition is also increasing, though not as significantly as the life expectancy increase. Striking to see is that in high income countries, the number of years lived with a health condition is higher than it is in lower income countries. This can probably be explained by the fact that healthcare in the higher income countries has improved and thus, because of proper treatment, people can live longer with a certain disease.