How much woman in the world
According to UN data portal, the world has not at any time had 5. The population of males in the world hit 2. Do Women Really Outnumber Men? The last World Population report revealed an estimated Access our full social media package with visuals and messages.
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In the map we see the sex ratio of populations: this is shown as the percentage of the total population which is female. Countries over 50 percent shown in blue have more females than males; those below 50 percent shown in red have fewer females. Most countries have a female share of the population between 49 and 51 percent within one percentage point of parity. Across the world there are differences in the sex ratio at different life stages. This imbalance in the male and female population can in some cases be traced back to birth: in some countries the number of boys and girls born each year is significantly skewed.
In the map we see the differences in sex ratio at birth across the world. Here the sex ratio is measured as the number of male births for every female births; a value greater than indicates there are more boys than girls born that year. A figure of would indicate that there are male births for every female births. The first striking point is that in every single country of the world there are more boys born than girls. This has been true for all years for which we have data as far back as in all countries of the world, as you can when you move the timeslider below the map further back.
Does this mean every country selects for boys prior to birth; for example, through induced abortion practices which preferentially select for boys? Not necessarily. In the absence of selective abortion practices, births in a given population are typically male-biased — the chances of having a boy are very slightly higher than having a girl. For most countries, there are around males per female births.
Why is this? In the most comprehensive study of its kind, Orzack et al. This produced the largest dataset available on the sex ratio throughout the stages of pregnancy. A key result from this study was that the sex ratio at conception is equal: there is no difference in the number of males and females conceived.
For births to be consistently male-biased, there must be gender differences in the probability of miscarriage through pregnancy. The study found that although the probability of miscarriage varies between genders across the course of a pregnancy, female mortality is slightly higher than male mortality over the full period:.
Some male-bias in births is what we expect with no deliberate gender selection through parents or society more broadly. There are, however, some key outliers in the world today: in countries including China, India, Vietnam, Pakistan, and Azerbaijan this ratio is very skewed. Most countries have a sex ratio at birth which is around the expected range of boys born for every girls.
There are exceptions to this: there are countries — most notably in Asia — with highly skewed sex ratios in favor of males. The preference in some countries for a son is seen in the overall sex ratio at birth figures above. But this bias is even stronger when we look at how this ratio is affected by the birth order of children.
In this visualization we look at the case of India and how sex ratios change from the 1st child in a family through to the 2nd, 3rd, 4th, and 5th born children.
It presents this data in two cases:. On the left-hand side we have the sex ratio at birth when the child is not the last. But we see that for the 2nd, 3rd, 4th and 5th born children, this ratio is skewed towards girls. In other words this shows us that when a girl is born, parents are more likely to have another child. It is evidence that parents are continuing to have children until they get a son.
Compare this to the right-hand side where we see the sex ratio when the child is the last. These ratios are much more skewed towards boys. Parents whose 1st child is a son are much more likely to stop having children. The sex ratio here is boys per girls. Combined we see a strong preference for a son in India: parents are more likely to continue having more children when the child is a girl and they are more likely to stop having children when they have a boy.
Now compare these ratios to that of Indonesia in the second row below. Parental choices do not point to a strong preference for a son or a daughter. In the third row we see that within India there are large differences in son preference across different states. From the study presented above we see that the sex of a child can, in some countries, be an important deciding factor for when parents stop having children.
But birth order also influences the likelihood of prenatal sex selection PSS i. We see evidence of this across several countries. Researchers looked at Indian national survey data from to to see how the sex of children and birth order affects the use of prenatal selection.
This was mainly a result of male selection for the 2nd or 3rd child within a family. When the firstborn or the first- and second-born siblings were female then a boy was much more likely the 2nd or 3rd child.
This skewed ratio can only be explained from prenatal sex selection in favor of boys. At a local level, a study of a large Delhi hospital known for maternal care showed very similar results. But this got significantly worse when the family already had a daughter: girls per boys if there was one previous girl and only girls per boys for two previous daughters.
Even for women who had not practiced sex-selection abortion, more mothers who had previously had a girl reported taking traditional medicines which were ineffective for sex selection purposes. These examples are of course not restricted to India. Many countries across Asia in particular have similar findings.
In this chart we see how the sex ratio in South Korea was affected by birth order. Here we see a very steep rise in the sex ratio of third-, fourth- and later children through the s. By the early s there were more than boys per girls for third-born children; for fourth-born or higher, the ratio was close to This occurred at a time the number of children per woman was falling quickly : in its fertility rate was 4.
Clearly sex ratios in China have also been affected by birth order. But we see a much more significant skew in the ratio for second or third-born children. For third-born children, the ratio was boys per girls, suggesting a high prevalence of sex selection abortions. South Korea provides an important example where the male bias can be successfully addressed. But for several countries across Asia this looks like a major challenge: the data shows that many parents still strongly prefer a son.
But how does this ratio look later in childhood? Does it change from newborns to five-years-olds? In the two charts here we see two perspectives: firstly a global map of the sex ratio at five years old. Just as with the sex ratio at birth, we see the highest ratios in several Asian countries where the share of boys is higher than we would expect.
In China, there is close to boys per girls at age five; in India, there are more than boys per girls. Secondly we see a scatterplot comparison of the sex ratio at birth on the y-axis versus the ratio at five years old on the x-axis.
The grey line here represents parity: a country which lies along this line has the same ratio at five years old as it does for birth. As we see, most countries lie above this line: this means the sex ratio for newborns is higher than for 5-year-olds. In other words, the male-bias tends to weaken through the first years of childhood. Why is this the case? As we explore in the next section of this entry: across most countries infant and child mortality rates are higher for boys than for girls.
This means fewer boys survive the first few years of life. For most countries this results in a decline in the sex ratio. Overall we see that despite higher child mortality in boys, the sex ratio at age five in the majority of countries is over this means boys still outnumber girls in childhood. From life expectancy to mental health ; substance use to cancer rates ; there are important differences in health outcomes between the sexes.
Here we focus on the youngest, asking, why do young boys die more often than girls? Child mortality measures the share of newborns who die before reaching their 5th birthday. In the chart below we see the comparison of child mortality by sex. Here, the mortality rate for boys is shown on the y-axis, and the mortality rate for girls on the x-axis. The grey line running diagonally across the chart marks where the mortality rate for both sexes is equal.
In countries which lie above the grey line, the rate for boys is higher than for girls. This is also true for infant mortality , which is the share of newborns who die within their 1st year of life. We study why India and Tonga are outliers here. Over the past half-century in particular, child mortality has been falling rapidly across the world. This has been true for boys and girls alike. It has been known for a long time that the mortality of boys is higher. Why is it the case that boys die more often than girls?
In this chart we see global mortality rates in infants across different causes in Just like the charts above, causes which lie above the grey line are more common in boys.
The chart shows that for all major causes of death, mortality is higher in boys. The sex differences in the causes of infant deaths were already documented almost a century ago: in an impressive paper published in , Bawkin explores the mortality sex ratio of specific diseases from countries across the world.
But overall, infant boys are more likely to die in childhood than girls. Boys are more vulnerable in two key ways: they are at higher risk of birth complications, and infectious disease. We explore the possible reasons for this below. From comparison of mortality rates in infant boys and girls, it becomes clear that boys are at higher risk of complications in the first few days of life: preterm births, asphyxia, birth defects and heart anomalies.
But why? First of all, boys are more likely to be born prematurely : the share of boys born before full-term pregnancy is higher than for girls. Boys tend to have a higher birthweight than girls — which can increase the risk of waiting to term to deliver — meaning that more boys are induced before the end of the pregnancy term.
The fact that preterm births are more common for boys contributes to this. Although boys are, on average, heavier than girls at birth, they are less physiologically mature at birth. This means they are at higher risk of having delayed physiological function such as lung function and adverse neurological outcomes.
The reason for this difference has been an important question for decades — the answer is still not clear. But there are some leading hypotheses: surfactant production for lung function has been observed earlier in female fetuses, leading to improved airway flow in the lungs; estrogen has been shown to affect lung development positively in females; males, on average, have a higher birthweight meaning they may trade-off increased size for functional development; and the uterus may be less hospitable to male fetuses — the introduction of a Y chromosome in females can create and immunoreactive response to the central nervous system.
This, combined with a higher risk of premature birth may explain why boys have higher rates of asphyxia, respiratory infections and birth defects. Boys are also at higher risk of infectious diseases such as syphilis, malaria , respiratory infections, tetanus and diarrheal diseases.
This is more generally true for a broad range of infections, spanning person-to-person, vector-borne, blood-borne, and food and water borne diseases. We see this clearly when we compare mortality rates for boys and girls in the earlier chart. But why are boys more susceptible to infection? Overall, boys have weaker immune systems. There are two key hypotheses for why. The Y-chromosome in boys increases their vulnerability. Biologically, males and females are differentiated by chromosomes: females have two X chromosomes XX and males one X and one Y chromosome XY.
Having two X chromosomes means that the newborn has a stronger immune system because X chromosomes contain a larger number of immune-related genes. This makes males more vulnerable to many infectious diseases. They are also more susceptible to specific genetic diseases where the defective genes are carried on either the X or Y chromosomes; this is because boys have only one X chromosome so a single recessive gene on that X chromosome results in the disease.
But the stronger immune response of females comes with a cost. Sex hormones may be another key reason for weaker immune systems in males.
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