In AP Human Geography, gender ratio (also called sex ratio) is the proportion of males to females in a population. Imbalances can result from selective abortion, differential mortality, or sex-selective migration, and they show up visually as lopsided bars on a population pyramid.
Gender ratio, which the CED calls sex ratio, is the balance of males to females in a population. A "normal" population has slightly more boys born than girls, but women tend to live longer, so the ratio shifts toward females in older age groups. When the ratio gets seriously out of balance, geographers want to know why.
The causes are the interesting part. Cultural preferences for sons can lead to sex-selective abortion (think China under the one-child policy or parts of India). Wars and dangerous occupations can reduce the male population. Labor migration can skew a place heavily male, like Gulf states that import millions of male construction workers, while leaving the sending regions disproportionately female. Per EK PSO-2.E.1, these patterns vary across regions and can be mapped and analyzed at different scales, so a country might look balanced overall while individual cities or villages are wildly skewed.
Gender ratio lives in Topic 2.3 (Population Composition) in Unit 2, supporting learning objective 2.3.A, which asks you to describe the elements of population composition geographers use. Sex ratio and age structure are the two big ones. It also feeds into 2.3.B, because population pyramids depict gender ratio directly. The left side shows males, the right shows females, and any asymmetry between the two sides is a gender ratio story waiting to be explained. EK PSO-2.E.1 specifically says sex ratio patterns vary by region and scale, which means the exam can hand you a map or pyramid from anywhere in the world and expect you to read the imbalance and reason about its cause.
Keep studying AP® Human Geography Unit 2
Age Sex Pyramid (Unit 2)
The population pyramid is where gender ratio becomes visible. Males stack on one side, females on the other, so a skewed gender ratio literally makes the pyramid lopsided. A bulge of working-age men often signals labor in-migration; missing men in older cohorts can signal past wars.
Age Structure (Unit 2)
Age structure and gender ratio are the two core ingredients of population composition. They work together, since gender imbalances usually concentrate in specific age groups rather than spreading evenly across the whole population.
Migration Patterns (Unit 2)
Migration is often sex-selective. When men migrate for work, the destination skews male and the origin skews female. This is one of the cleanest cause-and-effect chains you can write in an FRQ, connecting Topic 2.3 to the migration topics later in Unit 2.
Developed vs. Developing Countries (Units 2 & 7)
Gender ratio patterns track development. Developed countries tend toward female-heavy older populations because women outlive men, while some developing regions show male-heavy ratios tied to son preference or male labor migration. That same gendered lens returns in Unit 7 with women's roles in economic development.
Multiple-choice questions usually test gender ratio through population composition. A typical stem asks you to identify which element of composition is being described, or hands you a population pyramid and asks you to explain why one side is bigger than the other. The skill being tested is interpretation, not memorization. You need to look at a skewed pyramid or map and supply a plausible cause, like sex-selective migration, son preference, or differential mortality. Population data also shows up in FRQs built around map stimuli, such as the 2017 FRQ on rates of natural increase, where reading demographic patterns at different scales is the core task. If a pyramid appears, always check both the age axis and the male-female balance before answering.
Both are elements of population composition shown on a population pyramid, but they measure different things. Age structure is the vertical story, meaning how people are distributed across age groups. Gender ratio is the horizontal story, meaning how males compare to females within each bar. An MCQ asking about "distribution across age groups" wants age structure, not gender ratio.
Gender ratio (sex ratio) is the proportion of males to females in a population, and it is one of the core elements of population composition in Topic 2.3.
Imbalanced gender ratios come from causes like sex-selective abortion, differential mortality (women living longer, men dying in wars), and sex-selective labor migration.
On a population pyramid, males are on the left and females are on the right, so a skewed gender ratio shows up as asymmetry between the two sides.
Per EK PSO-2.E.1, sex ratio patterns vary by region and scale, so a balanced national ratio can hide major imbalances in specific cities or villages.
Older age cohorts almost always skew female because women have longer life expectancy than men.
Gender ratio is not the same as age structure; age structure describes the distribution of people across age groups, while gender ratio compares males to females.
Gender ratio, called sex ratio in the CED, is the proportion of males to females in a population. It's a key element of population composition in Topic 2.3 and is read directly off a population pyramid.
The big three causes are sex-selective abortion driven by son preference (as in China under the one-child policy), differential mortality (women outlive men, and wars kill more men), and sex-selective migration (male workers moving to places like the Gulf states).
No. Age structure is the distribution of people across age groups, while gender ratio compares males to females. A practice question asking about "distribution across age groups" is testing age structure, not gender ratio.
Usually either cultural son preference leading to sex-selective abortion, or heavy male labor in-migration. Gulf states like Qatar and the UAE skew strongly male because they import large numbers of male construction and service workers.
Compare the left side (males) to the right side (females) within each age bar. A balanced population is roughly symmetrical; a bulge of working-age men suggests labor migration, and female-heavy elderly cohorts reflect women's longer life expectancy.
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