The received wisdom that men do not live as long as women has been challenged by analysis of statistics spanning two centuries.
The study claims that men have up to a 50 per cent chance of outliving women, despite the average male lifespan being shorter. Men who are married and have a degree have the best chance, it found.
Study author Jesus-Adrian Alvarez, at the Interdisciplinary Centre on Population Dynamics in Denmark, told The National: "Between 25 per cent and 50 per cent of men have lived more years than women in 199 countries, over a period of more than 200 years. This finding clearly indicates that there are more nuances to disparities in longevity, as not all women outlive all men."
The findings are published in the open access journal BMJ Open.
The researchers used a particular statistical approach — the ‘outsurvival’ statistic — to study gender differences in deaths in 199 populations from every continent over a period of 200 years.
This statistic measures the probability that a person from a population with a high death rate will outlive someone from a population with a low death rate.
Data analysis showed that since 1850 the probability of males outliving females has, at all points in time and across all populations, remained within the boundary of 25 per cent and 50 per cent, with a few exceptions where it went even higher.
These were Iceland in 1891; Jordan in 1950–54; Iran in 1950–64, Iraq in 1960–69; before 1985 in Bangladesh, India and the Maldives; and between 1995 and 2010 in Bhutan.
The rise and fall in the respective genders' life expectancy were attributed mainly to smoking and other behavioural differences.
Childhood deaths were also a factor, for example in South Asian countries where values were above 50 per cent for men in the 1950s and 1960s. The death rate for children under 5 in India was higher for girls than for boys and has remained higher for girls in recent years.
But fewer girls than boys above the age of 15 have died since the 1980s, "balancing out" the disadvantage at younger ages, they explain.
Certain external factors seem to play a key role. For example, between 2015 and 2019, the probability of males outliving females was 40 per cent across the entire US population.
But this statistic varied, depending on marital status and educational attainment: the probability of men outliving women was 39 per cent for those who were married and 37 per cent for those who were not. It was 43 per cent for those with a university degree and 39 per cent for those without a school-leaving qualification.
What is more, married men with a degree have an advantage over unmarried women educated only to high school level. Couples influence each other’s health, and this is particularly true for men, who benefit more than women from being in a stable relationship, the researchers found.
“A blind interpretation of life expectancy differences can sometimes lead to a distorted perception of the actual inequalities [in lifespan],” they write.
“Not all females outlive males, even if a majority do. But the minority that do not is not small.
"A small number of males will live very short lives to result in that difference. For example, more baby boys die than baby girls in most countries."
The data nevertheless shows that the death rate has fallen faster for women overall, than for men under the age of 50, especially in the first half of the 20th century, largely as a result of a sharp decline in infant and child deaths.
And men have not only maintained their survival disadvantage at younger ages, but at older ages, too. They are more prone to accidents and murders in their 20s and 30s, and they tend to smoke and drink more, leading to higher cancer prevalence and death in their 60s.
A more nuanced approach to gender differences in survival is needed, say the researchers. “Efforts in reducing lifespan inequalities must thus target diverse factors, causes and ages,” they conclude.
