Why Are There More Men in the World Than Women?

While there are more men than women from a global perspective, when you look at different demographics and geographic locations, the balance is often flipped.

When you look around in a crowded space, such as Times Square or an auditorium filled with people, it seems like there is generally an equal distribution of men and women. As a global population, however, we are not equally split between genders. There are roughly 102 men for every 100 women on the planet, which strikes some people as unusual. Nature doesn’t do anything randomly, so there must be some explanation for this peculiar population statistic. Evolution? Behavioral characteristics? Birth rate?

As it turns out, the answer is related to all three of those factors…

The Battle of the Sexes

While the population statistic may be 102 men : 100 women, the birth rate is even more skewed. Approximately 107 men are born for every 100 women, but over time that number seems to even out. Over the course of millions of years of evolution, nature has a way of working out the kinks, and this imbalanced birth rate is evidence of that.

The sex of any fetus is dependent on a number of factors, including the parents’ health, occupation, age, race, behavioral habits, hormonal treatments, exposure to environmental toxins, stress, previous childbirth experiences and the mother’s ovulation cycle. All of those factors contribute to the imbalanced ration of 107:100, but there is a good reason for stacking the deck in favor of males.

Males at a risk

By nature, male infants are more likely to suffer some sort of health issue or premature death. New born males are at a biological disadvantage in survival as they are more vulnerable to perinatal conditions, and infectious diseases like respiratory infections and intestinal infections.

Furthermore, as men age, they are more likely to develop serious health issues and engage in risky behavior. Additionally, throughout history, men have been more likely to kill one another than women. Countless wars, conflicts and even violent domestic disputes usually end with a much greater loss of life for males. This has been true since the earliest days of our species’ development, so it makes sense that nature had to compensate.

These elements cause male populations to decline at a faster rate than female populations over time, resulting in the global population ratio of 101 men : 100 women.

The problem of son preference

The remaining difference in the ratio can be explained by certain social and cultural traditions, such as abortions and gendercide, since male infants are more highly desired than females in some parts of the world. Son preference is highly prevalent in several countries in East Asia, South Asia, Middle East and North Africa. Sons are preferred, especially in agrarian economies, since they have a higher wage-earning capacity and also since they ‘continue the family line’. Girls are often considered an economic burden since they typically become members of the husband’s family, ceasing to have any responsibility for their parents in old age.

Discriminatory practices against girls, such as the dowry system (in some countries), also contribute to this unfair preference for male children. Since prenatal sex determination became available in the 1980s, it has majorly contributed to imbalances in the sex ratio in the form of sex-selective abortion. Sex-selective abortion became very common in Asian countries like China, Korea, Taiwan and India. In South Korea, a shocking 80,000 female fetuses were aborted between 1986 and 1990, a number equivalent to about 5 percent of all female births in that time period. (Source)

Additionally, girls may sometimes not be counted in the census enumerations due to the birth of baby girls going unreported. For example, in China during the 1980s, couples, who wanted sons but feared facing harsh penalties if they had too many children, gave their baby girls away for adoption without registering their births.

After birth, discrimination against daughters leads to neglect of their nutrition and health care requirements, resulting in higher female mortality. Unequal access to health care, especially in cases where the health care costs have to be borne by the family, is the most important contributing factor towards female mortality.

Evening the Scales

While there are more men than women from a global perspective, when you look at different demographics and geographic locations, the balance is often flipped. As mentioned earlier, male infants are more likely to die from complications during birth and in the first few weeks of life, but the imbalance starts even earlier than that. Research has also shown a higher mortality rate for male embryos in the first week of pregnancy and in the final trimester (source).

As you move up the age scale, particularly past the age of 60, there is a clear advantage for women, who tend to have longer life expectancies than men. In most parts of the world, women live longer than men, mainly owing to a higher risk of cardiovascular diseases in men. The global average life expectancy for women is 71.1 years; for men around the world, life expectancy averages 67 years (source).

In some countries, like Belarus, Russia and Lithuania, the life expectancy gap is even greater – female life expectancy is more than 11 years longer than men (source).

Male mortality is on the decline in European established democracies and the gender gap in life expectancies is slowly becoming smaller. Current trends in Iceland and other Scandinavian countries indicate that, by the year 2050, the difference between life expectancies will whittle down and men will live as long as women. Unfortunately, this gap continues to grow in Russia where women live on the average 13 years longer. (Source)

In terms of geographical location, some countries in the Middle East have more than 250 men : 100 women (e.g. United Arab Emirates and Qatar). At the other extreme, the Caribbean island of Martinique has a ratio of 85 men : 100 women (Source). Each country and demographic has a unique set of factors that affect the balance of men and women, so if anything, it is remarkable that the balance of men and women is as close as it is!

The Evolutionary Edge

As always, natural selection does have a hand in keeping the battle of the sexes relatively even. For example, if it were far less common for males to be born than females, reproduction of the species would still be important, and the males would have a reproductive advantage, and would be able to have many children. The genetic makeup of the males would predispose them to male offspring (since the males’ parents obviously had that predisposition in their genetic makeup).

Therefore, the number of males predisposed to male births would begin to increase until a balance was once again struck. In theory, all population dynamics would move towards a 50:50 split, but humans are a complex example, which is why nature has to compensate in various ways. This is known as the Fisher’s Principle – that every species would tend towards an even gender divide over time, since the minority gender would always possess a sexual advantage, and thus pass that advantage on to their offspring.

It’s pretty hard to find any fault in the natural order of gender, and while you may feel like a slight minority as a woman, at times, in the grand scheme of things, the difference isn’t all that great.  If you want to live in a world dominated by males, visit the Middle East, but if you want to relax somewhere with more females than males, take a trip to the Caribbean!


Harvard Health Publications
National Center for Biotechnology Information
World Health Organization
Women live longer – a research paper

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