1.3 Population and Culture

Population Geography

Understanding how the human population is organized geographically helps students make sense of cultural patterns, the political organization of space, food production issues, economic development concerns, natural resource use and decisions, and urban systems.

Explanations of why the population is growing or declining in some places are based on patterns and trends in fertility, demographic mortality, and migration. Analyses of refugee flows, immigration, and internal migration help us understand the connections between population phenomena. For example, environmental degradation and natural hazards may prompt population redistribution at various scales, which in turn creates new pressures on the environment, culture, and political institutions.

Demographic Transition

Demography is the study of how human populations change over time and space. It is a branch of human geography related to population geography, which is the examination of the spatial distribution of human populations. Geographers study how populations grow and migrate, how people are distributed around the world, and how these distributions change over time .

Geographers study where and why people live in particular locations. Neither people nor resources are distributed uniformly across Earth. In regards to population growth, geographers emphasize three elements: the population size, the rate of increase of world population, and the unequal distribution of population growth. Geographers seek to explain why these patterns exist.

“Introduction to Human Geography: Chapter 2.1 Population” by R. Adam Dastrup is licensed under CC BY 4.0[/footnote]

For most of human history, relatively few people lived on Earth, and the world population grew slowly. Only about five hundred million people lived on the entire planet in 1650 (that’s less than half India’s population in 2000). Things changed dramatically during Europe’s Industrial Revolution in the late 1700s and into the 1800s, when declining death rates due to improved nutrition and sanitation allowed more people to survive to adulthood and reproduce. The population of Europe grew rapidly. However, by the middle of the twentieth century, birth rates in developed countries declined, as children had become an economic liability rather than an economic asset to families. Fewer families worked in agriculture, more families lived in urban areas, and women delayed the age of marriage to pursue education, resulting in a decline in family size and a slowing of population growth. In some countries (e.g., Russia and Japan), population is actually in decline, and the average age in developed countries has been rising for decades. The process just described is called the demographic transition.

Population Reference Bureau. (2011, October 26) 7 billion and counting [Video] Youtube. https://www.youtube.com/watch?v=d1dIAtvSFLM&t=83s

At the beginning of the twentieth century, the world’s population was about 1.6 billion. One hundred years later, there were roughly six billion people in the world, and as of 2011, the number was approaching seven billion. This rapid growth occurred as the demographic transition spread from developed countries to the rest of the world. During the twentieth century, death rates due to disease and malnutrition decreased in nearly every corner of the globe. In developing countries with agricultural societies, however, birth rates remained high. Low death rates and high birth rates resulted in rapid population growth. Meanwhile, birth rates—and family size—have also been declining in most developing countries as people leave agricultural professions and move to urban areas. This means that population growth rates—while still higher in the developing world than in the developed world—are declining. Although the exact figures are unknown, demographers expect the world’s population to stabilize by 2100 and then decline somewhat.

In 2010, the world’s population was growing by about eighty million per year, a growth rate found almost exclusively in developing countries, as populations are stable or in decline in places such as Europe and North America. World population increase is pronounced on the continent of Asia: China and India are the most populous countries in the world, each with more than a billion people, and Pakistan is an emerging population giant with a high rate of population growth. The continent of Africa has the highest fertility rates in the world, with countries such as Nigeria—Africa’s most populous and the world’s eighth most populous country—growing rapidly each year. The most striking paradox within population studies is that while there has been marked decline in fertility (a declining family size) in developing countries, the world’s population will grow substantially by 2030 because of the compounding effect of the large number of people already in the world—that is, even though population growth rates are in decline in many countries, the population is still growing. A small growth rate on a large base population still results in the birth of many millions of people.

Earth’s human population is growing at the rate of about 1.4 percent per year. If the current growth rate continues, the human population will double in about fifty years to more than twelve billion. The current population increase remains at about eighty million per year. A change in the growth rate will change the doubling time. Between 2010 and 2050, world population growth will be generated exclusively in developing countries.

Figure 1.30 Population Growth from Year 1 to Year 2010 AD

The three largest population clusters in the world are the regions of eastern China, south Asia, and Europe. Southeast Asia also has large population clusters. Additional large population centers exist in various countries with high urbanization. An example is the urbanized region between Boston and Washington, DC, which includes New York City, Philadelphia, Baltimore, and neighboring metropolitan areas, resulting in a region often called a megalopolis. The coastal country of Nigeria in West Africa and the island of Java in Indonesia are good examples of large population clusters centered in the tropics.

Social dynamics and geography will determine where the new additions to the human family will live. Providing food, energy, and materials for these additional humans will tax many countries of the world, and poverty, malnutrition, and disease are expected to increase in regions with poor sanitation, limited clean water, and lack of economic resources. In 2010, more than two billion people (one-third of the planet’s population) lived in abject poverty and earned less than the equivalent of two US dollars per day. The carrying capacity of the planet is not and cannot be known. How many humans can the earth sustain in an indefinite manner? There is the possibility that we have already reached the threshold of its carrying capacity.

Human population will continue to grow until it either crashes due to the depletion of resources or stabilizes at a sustainable carrying capacity. Population growth exacts a toll on the earth as more people use more environmental resources. The areas most immediately affected by increased populations include forests (a fuel resource and a source of building material), fresh water supplies, and agricultural soils. These systems get overtaxed, and their depletion has serious consequences. Type C climates, which are moderate and temperate, are usually the most productive and are already vulnerable to serious deforestation, water pollution, and soil erosion. Maintaining adequate food supplies will be critical to supporting a sustainable carrying capacity. The ability to transport food supplies quickly and safely is a major component of the ability to manage the conservation of resources. Deforestation by humans using wood for cooking fuel is already a serious concern in the arid and dry type B climates .

Figure 1.31

Population Demographics

The Industrial Revolution, which prompted the shift in population from rural to urban, also encouraged market economies, which have evolved into modern consumer societies. Various theories and models have been developed to help explain these changes. For example, in 1929, the American demographer Warren Thompson developed the Demographic Transition Model (DTM) to explain population growth based on an interpretation of demographic history. A revised version of Thomson’s model outlines five stages of the demographic transition from traditional rural societies to modern urban societies.

Stage 1: Low Growth Rate

Humans have lived in the first stage of the DTM for most of our existence. In this first stage, CBRs and CDRs fluctuated wildly regionally, globally, and over time because of living conditions, food output, environmental conditions, war, and disease. Ultimately, the natural increase of the world was stable because CBRs and CDRs were about equal. However, around 8,000 BCE, the world’s population grew dramatically due to the agricultural revolution. During this time, humans learned to domesticate plants and animals for personal use and became less reliant on hunting and gathering for sustenance. This allowed for more stable food production and allowed village populations to grow. However, war and disease prevented population growth from occurring globally.

Stage 2: High Growth Rate

Around the mid-1700s, global populations grew ten times faster than in the past because of the Industrial Revolution. The Industrial Revolution brought with it a variety of technological improvements in agricultural production and food supply. Increased wealth in Europe and later North America because the Industrial Revolution meant more money and resources could be devoted to medicine, medical technology, water sanitation, and personal hygiene. Sewer systems were installed in cities; thus, public health improved. All of this dramatically caused CDRs to drop around the world. At first, CBRs stayed high as CDRs dropped, causing populations to increase in Europe and North America. Over time, this would change.

Africa, Asia, and Latin America moved into Stage 2 of the demographic transition model 200 years later for different reasons than their European and North American counterparts. First, the medicine created in Europe and North America was brought into these developing nations creating what is now called the medical revolution. This revolution or diffusion of medicine to this region caused death rates to drop quickly. However, while the medical revolution reduced death rates, it did not bring with it the wealth, improved living conditions, and development that the Industrial Revolution created. As a result, global population growth is most significant in the regions still in Stage 2.

Figure 1.32

Stage 3: Moderate Growth Rate

Today, Europe and North America have moved to Stage 3 of the demographic transition model. A nation moves from Stage 2 to Stage 3 when CBRs begin to drop while CDRs remain low or continue to fall. It should be noted that the natural rate of increase in nations within Stage 3 is moderate because CBRs are somewhat higher than CDRs. The United States, Canada, and European nations entered this stage in the early 20th century. Latin American nations entered this stage later in the century.

Advances in technology and medicine cause a decrease in IMR and overall CDR during Stage 2. Social and economic changes bring about a decrease in CBR during Stage 3. Countries that begin to acquire wealth tend to have fewer children as they move away from rural-based development structures toward urban-based structures because more children survive in childhood. As a result, the need for large families for agricultural work decreases. Additionally, women gained more legal rights and chose to enter the workforce, own property, and have fewer children as nations moved into Stage 3.

Stage 4: Return to Low Growth Rate

A country enters Stage 4 of the demographic transition model when CBRs equal to or become less than CDRs. When CBRs are equal to CDRs, a nation will experience zero population growth (ZPG). This occurs in many countries where girls do not live as long as they reach their childbearing age due to gender inequality.

A country in the first two stages of the transition model will have a broad base of young people and a smaller proportion of older people. A country in Stage 4 will have a much smaller base of young people (fewer children) but a much larger population of elderly (decreased CDR). A country with a large youth population is more likely to be rural with high birthrates and possibly high death rates, helping geographers analyze a nation’s health care system. Moreover, a country in Stage 4 with a large elderly population will have fewer young people supporting the economy. These two examples represent the dependency ratio mentioned earlier in this chapter. This ratio is the number of young and older adults dependent on the working force.

Human geographers like to focus on the following demographic groups: 0-14 years old, 15-64 years old, and 65 and older. Individuals ages 0-14 and over 65 are considered dependents (though this is changing in older generations). One-third of all young people live in developing nations. Moreover, this places considerable strain on those nations’ infrastructure, such as schools, hospitals, and daycare. Older individuals in more developed nations (MDL) benefit from health care services but require more help and resources from the government and the economy.

Another ratio geographers look at is the number of males compared to females, called the sex ratio. Globally, more males are born than females, but males have a higher death rate than females. However, understanding a country’s sex and dependency ratios helps human geographers analyze fertility rates and natural increases. As noted earlier, population growth has increased dramatically in the last century. However, every country is still in Stage 1, and only a few have moved into Stage 4. Most of the world is either in Stage 2 or 3, which both have higher CBRs than CDRs, creating a human population of over 7.5 billion today.

Stage 5: Population Decline

Many demographers believe a new stage in the DTM should be added to address issues starting to develop in countries within Europe and Japan. In this final stage, CBR would be extremely low and an increasing CDR. This would cause the area’s NIR to be negative, leading to declining population growth. This may create an enormous strain on a country’s social safety net programs as it tries to support older citizens who are no longer working and contributing to the economy.

Geographers are interested in how populations are distributed spatially. It may not be good enough to say how many people are in a particular area, but instead, it should be normalized by some other factor. If two countries have the same population, but one is twice as big as the other in physical area, the populations will be distributed in different ways. For this situation, geographers use density. Population density is the number of people in an area divided by the total land area. Another way of thinking about density is physiological density, which is the number of people in an area divided by the amount of land under cultivation. This gives an idea of the amount of arable land being used to support a population.

Figure 1.33 Population Density.

Beyond area-based densities, demographers will normalize the size of different subpopulations by dividing by the total population; in other words, creating ratios or percentages. These can then be compared from location to location. For example, chances are that New York City, being the most populous city in the United States, will have the largest raw numbers for any particular demographic (race, age group, or multitudes of other population breakdowns). But new patterns may emerge in seeing if these demographics are comparatively large or small as a percentage.

Figure 1.34 Population pyramid examples (by author)

One common method of studying population is by looking at the distribution of people’s ages within a location. Visually this is done through population pyramids, which give a window into the age-based composition of a population as opposed to the geographical distribution. This horizontal bar graph separates males and females and breaks each into smaller cohorts. Cohorts are groups of people who share a common temporal experience. Your graduation year sets you in a certain cohort with others that graduate at the same time. Likewise, those that are born in the same time period are a cohort. In population pyramids, cohorts are generally grouped into 5-year intervals. The shape of the pyramids are generally categorized as expansive, stationary, or constrictive. Expansive locations have a wide base and are experiencing high population growth. Stationary locations have a base close to the size of other cohorts, meaning they are either slowly growing or not growing. Constrictive locations have a narrow base, showing population decline. Note that these categories are generally applied to countries; when looking at smaller geographies like cities, the same patterns don’t tend to exist. People commonly move in and out of cities, but are much less likely to leave a country. That means that classic college towns will always have a large cohort of people from about age 20–30; older people move out, and younger people keep moving in, rather than a cohort aging through the location.

Looking at broader cohorts can be illustrative of patterns of population, especially as your geography gets smaller. Counties and cities look at three broad cohorts:

• Youth cohort: population under age 15
• Middle cohort: population between 15 and 64
• Old-age cohort: population 65 and older

The middle cohort is generally seen as the population that is economically productive. The youth and old-age cohorts are generally aged too young or too old to be a part of the labor market. These are of course quite broad comparisons and are not looking at the employment status of every single person. If the youth and old-age cohorts are combined, and divided by the size of the middle cohort, a dependency ratio is calculated. This calculates a ratio of the economically unproductive to the economically productive. Higher ratios mean that there are fewer workers supporting larger numbers of people, which can hurt economic sustainability.

Birth rates

How populations change is described with a fairly simple equation:

Population = Previous Population + Births – Deaths + Immigration – Emigration

The next section will discuss migration. This part outlines natural changes to the population; namely births and deaths. While total numbers of births and deaths are what will change the population, demographers often look at crude rates. The crude birth rate is the total number of births in a given time period per 1,000 people in a population. The crude death rate is the same but for deaths. A narrower slice at looking at natural increases is to understand the total fertility rate (TFR). This is the average number of children born by females aged 15-49, which is the age range typically tied to reproduction. Demographers look at a TFR of 2.1; if TFR falls below this number, there will be a natural decline in population, as not enough births are happening for replacement rate.  According to the CIA World Factbook, the country with the highest total fertility rate is Niger at 6.49. The United States has the 143rd highest value at 1.87. Why isn’t the United States population decreasing?

Migration

Migration is the other way that populations change. Migration is split between emigration (moves from a place) and immigration (moves to another place). A trick to remember this distinction is that you Exit when you Emigrate and you come In when you are an Immigrant. The difference is whether you are talking about people coming to or going from a particular location.

Other ways to categorize migration are by distance and choice. Physical and social distances are different between international and internal migration. International migration is from one country to another, while internal migration is moving from one part of a country to another part. Voluntary and forced migration is about the migrant’s choice; clearly voluntary migration is based on an individual’s choice while forced migration is against an individual’s will.

Migration, especially internationally, is not as easy as just wanting to leave a place or wanting to go to a place. Often there are barriers to movement. Absorbing barriers are those that completely block movement, whereas permeable barriers are those that weaken movement but still allow some diffusion. These barriers can be physical or social. A physical barrier may be an ocean, whereas social barriers may be walls, passports, and quota policies. The Berlin Wall, for example, was a social policy to separate democratic West Berlin from Communist East Berlin. This barrier was fairly permeable for West Berliners, who were free to enter East Berlin, but essentially an absorbing barrier in the other direction for East Berliners.

Race and ethnicity

One common demographic distinction to observe is that of race and ethnicity. Race and ethnicity is an identity in a culture that shapes the opportunities and disadvantages people may see in a society. As you will read about in the link below, race is something that does exist in humanity in the social sense, but not the biological sense. In other words, race is real because people think it’s real. Ethnicity, again as you will read below, is at times used as an euphemism for race but is a separate concept.

Though race and ethnicity are enforced strongly by society, there is also a significant individual component. One can see the competition between the individual and the society in looking at historical Census forms where people answer to their racial or ethnic identities. The Census Bureau has a database showing census forms from each decennial census. Early on, these forms were completed by Census employees who themselves could designate a person’s race. Later forms allow for individuals to fill out and return forms, answering the questions themselves. But, there is still the battle between individual and social definitions when looking at the terminology used for race. View the 2010 Census form; there is an entry for “Black, African Am., or Negro.” In 2010, this entry was controversial due to the inclusion of the anachronistic term “negro.” The argument was that some individuals, raised in a bygone era, still self identify as negro. Again, this was controversial. In looking at the more recent 2020 Census form, the category has been shortened to “Black or African American.” Ethnicity, of which the US Census Bureau only defines as Latino/a origin, is a separate question from race.

Figure 1.35

As described in the above chapter, one of the primary geographical connections with race is residential segregation. This pattern is clearly demonstrated by looking at the Racial Dot Map created by the Weldon Cooper Center for Public Service at the University of Virginia. In the interactive map linked above, there is one dot on the map for every person in the United States as of the 2010 Census. As a dot density map, the dots are randomly placed within census blocks and colored based upon the racial identity of individuals. The screenshot image to the right shows the pattern of residential segregation in Baltimore, Maryland. The map shows the white population with blue dots and the black population with green dots. The 2010 data still shows the classic “Black butterfly” shape of residential segregation in Baltimore that has existed for decades.

Many cities in the United States have stark dividing lines between black and white neighborhoods. Of course, divisions between other racially-concentrated neighborhoods exist as well, but the history of residential segregation in the United States is largely a black/white phenomenon.

Urbanization and Family Size

As countries move from an agricultural to an industrial economy, there is a major shift in population from rural to urban settings. The Industrial Revolution of the nineteenth century ushered in major technological developments and changes in labor practices, which encouraged migration from the farm to the city. Because of increased mechanization, fewer farm workers are needed to produce larger agricultural yields. At the same time, factories in urban areas have a great need for industrial workers. This shift continued into the information age of the late twentieth century and continues in many parts of the developing world in the current century.

Figure 1.36 Rural-to-Urban Shift

Wikimedia Commons – CC BY-SA 2.0.

A basic principle of population growth that addresses this rural-to-urban shift states that as countries industrialize and urbanize, family size typically decreases and incomes traditionally increase. Though this may not be true in all cases, it is a general principle that is consistent across cultural lines. Agricultural regions generally have a larger average family size than that of their city counterparts. Fertility rate is the average number of children a woman in a particular country has in her lifetime, whether or not they all live to adulthood. If a fertility rate for a given country is less than 2.1—the replacement level—the population of that country is in decline, unless there is significant immigration. A fertility rate greater than 2.1 indicates that the country’s population is increasing. Some children will never reach reproductive age nor have children of their own, so the replacement rate has to be slightly greater than 2. The concept of fertility rate is slightly different from the term family size, which indicates the number of living children raised by a parent or parents in the same household. In this textbook, family size is used to illustrate the concept of population growth and decline.

Population Demands

A country’s demographic statistics can be illustrated graphically by a population pyramid. A population pyramid is essentially two bar graphs that depict male and female age cohorts either in absolute size or as a percentage of the total population. Male cohorts are typically shown on the left side of the pyramid, and females are on the right side.

The shape of a country’s population pyramid tells a story about the history of its population growth. For example, a high-growth-rate country has a pyramid that is narrow at the top and wide at the bottom, showing that every year more children have been born than the year before. As family size decreases and women in a society have fewer children, the shape of the pyramid changes. A population pyramid for a post-industrialized country that has negative growth would be narrower at the bottom than in the middle, indicating that there are fewer children than middle-aged people. Four basic shapes indicate the general trends in population growth:

1.      Rapidly expanding

2.      Expanding

3.      Stationary

4.      Contracting

These shapes also illustrate the percentage of a population under the age of fifteen or over the age of sixty-five, which are standard indicators of population growth. Many postindustrial countries have a negative population growth rate. Their population pyramids are narrow at the bottom, indicating an urbanized population with small family sizes.