Everywhere in the world women live longer than men – but this was not always the case. The available data from rich countries shows that women didn’t live longer than men in the 19th century. What’s the main reason women are more likely to live longer than men? Why has this advantage gotten larger over time? The evidence is limited and we have only some solutions. We know that biological, behavioral and environmental factors play a role in the fact that women have longer lives than men, However, we’re not sure what the contribution of each one of these factors is.

Independently of the exact amount, we can say that a large portion of the reason why women live longer than men today, but not previously, has to relate to the fact that certain key non-biological factors have changed. What are these factors that have changed? Some are well known and relatively straightforward, like the fact that men smoke more often. Some are more complex. For example, there is evidence that in rich countries the female advantage increased in part because infectious diseases used to affect women disproportionately a century ago, so advances in medicine that reduced the long-term health burden from infectious diseases, especially for survivors, ended up raising women’s longevity disproportionately.

Everywhere in the world women tend to live longer than men

The first chart below shows life expectancy at birth for men and women. We can see that all countries are above the diagonal parity line – it means that in all nations baby girls can expect to live longer than a new boy.1

The chart above shows that, while the advantage for women exists in all countries, country-specific differences are huge. In Russia, women live 10 years longer than males. In Bhutan, the difference is only half a year.

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In the richer countries, the longevity advantage for women was not as great.

Let’s examine how the female longevity advantage has changed over time. The following chart shows the male and female lifespans at birth in the US during the time period between 1790 and 2014. Two points stand out.

The first is that there is an upward trend. Men and women in the US live much, much longer than they did 100 years ago. This is in line with historical increases in life expectancy everywhere in the world.

The gap is growing: Although the advantage of women in life expectancy used to be very small It has significantly increased over time.

Using the option ‘Change country from the chart, you are able to verify that these two points also apply to other countries with available information: Byte-on.org.au/index.php/Why_Women_Live_Longer_Than_Men Sweden, France and the UK.