Eugenics is the “science” of improving the human population by encouraging only a specific group of people to breed. It generally favors the growth of one race over others within a society. Eugenics was popular in Europe in the early twentieth century, but continues to be influential in some parts of the world to this day.

A census is an official government survey of the population of a government’s country. It usually includes questions about race, gender, religious identity, income, and a great many other things. In the United States, it is conducted every ten years and is used to determine representation in Congress (among other things).

Countries that discourage or ban the use of contraceptives are more likely to experience all of the provided answer options. High death rates result from the rampant spread of sexual disease, particularly AIDS. High birth rates result from the inability of women to control the reproductive process, which is of course linked to gender inequality. Many sociologists and historians agree that the relatively rapid increase in gender equality in many parts of the world in the last fifty years has been primarily caused by the availability of contraception, which allows women to dictate when, and with whom, they have children.

An “expansive population policy” is an official government policy designed to encourage the population to conceive and raise multiple children. Unlike a “restrictive population policy,” its primary goal is to increase the rate of population growth to prevent the economic and social welfare problems that arise with an aging population. “Expansive population policies” are most common in Western and Northern Europe where birth rates are some of the lowest in the world. Countries like Sweden, France, the U.K., Germany, and Italy have some form of “expansive population policies” in place.

Most studies and statistics on the subject demonstrate that any country that prioritizes education and providing universal access to education is likely to see a decline in the rate of its population growth. This is because as people become better educated they have more opportunities open to them and more control over their lives - this is particularly significant for women. Women who are well-educated are less likely to have unplanned pregnancies, less likely to have large families, and more likely to start those families at a later age. All of this contributes to a decline in the rate of population growth, or, in geographic parlance, a decline in the “natural increase rate.”

China's one-child policy has historically featured all of the following: awareness campaigns, inspections, fines, and forced abortions.

Eugenics involve the set of beliefs and practices that aim to improve the genetic quality of the human race. During the Progressive Era eugenics was accepted as a method of preserving and improving the dominant population groups. Today, eugenics is associated with racist and nativist elements. 

The Irish Potato Famine began in the middle of the nineteenth century and by the end of that century, the population of Ireland had been reduced by half. The rural poor in Ireland (the vast majority of the population at the time) had become dependent on the potato to sustain themselves, and when the crop failed due to potato blight, people starved by the millions or emigrated in desperation to escape the same fate. This incident provides many lessons (not least of all to resist the urge to become dependent on one seemingly super-crop) and continues to inform political relations to this day (e.g. between Ireland and Great Britain, and Ireland and the United States).

When the Europeans arrived in the New World, the population of the Americas was somewhere between thirty and one hundred million people. (Scholars frequently disagree over this statistic.) They arrived bringing a type of systematic violence unfamiliar to many of the native people, and these atrocities were responsible for significant loss of life, but far more native people were killed by the diseases that the Europeans brought with them. When people have had no exposure to a disease in their history, they will not have developed any natural immunities or defences to it; this makes them much more vulnerable to the disease than the carriers. The Europeans had been living with, and dying from, smallpox for centuries, but the Native Americans had not. The disease spread rapidly through North and South America, usually faster than the Europeans could move themselves, and decimated the native population. By some estimates, as many as ninety percent of the native population succumbed to the disease.

The Black Death was carried into Europe in the 1300s by fleas on rats aboard trading ships arriving in the powerful Italian city-states. The continent had experienced previous incarnations of “the plague” and would experience several more in the centuries to come, but this particularly incarnation spread like wildfire through the European population. Within five years the population of Europe was reduced by one-third; whole towns and regions were lost to history.