SOCI 210: Sociological perspectives

Agenda

  1. Administrative
  2. Studying populations
  3. Demographic theories

Studying populations

Black and white photo of a crowd of people, mainly facing in the same direction away from the camera.

Studying populations

photograph of a large group of people froma distance. They are all facing the same way.

Demography

  • Study of populations at a macro-scale
  • At its most basic: understanding the ways populations grow, shrink, and otherwise change
  • Relationship between population and other sociological factors

Population characteristics

  • Overall size
  • Proportions of socially relevant categories
    Ethnicity, gender, religion, etc.
  • Rates of change in these populations
  • Theories and mechanisms of change in these populations

Studying populations

Three factors affect changes in population size:

Birth

  • Crude birth rate
    Number of children born in a given time period, per 1,000 population
  • Fertility rate
    Average number of children that a childbearing person would have over their lifetime, assuming current rates by age

Death

  • Crude death rate
    Number of deaths in a given time period per 1,000 population
  • Age- and sex-specific mortality rates
    E.g. infant mortality (number of children who die within a year of birth, per 1,000 live births)

Migration

  • Immigration versus emigration
    Immigration is migration into a country, emigration is migration out of a country
  • Net number of migrants
    Immigrants minus emigrants

Studying populations

Total growth = (Birth) – (Death) + (Migration)

Bar chart labeled 'Population change: Canada 2016-17'. There are two bars, one labeled 2016 going to about 36.5 million, the other labeled 107 going to about 36.9 million. Between them there are three arrows. One (pointing up) says 'Births: 376,291'. The next (pointing down) says 'Deaths: 276,649'. The last (pointing up) saysk 'Net migration:360,358'

Studying populations

Population pyramids
(a.k.a. age pyramids)

  • Ubiquitous visual tool in demography
  • Picture of the ‘shape’ of an entire population
  • Shows size of a population at different ages
  • Can compare sub-populations on right and left
    (traditionally gender binary)
Nearly symmetric chart. The vertical axis in the center is labeled age (0 to 100). The horizontal axis is labeled 'Male population' on the left and 'Female population' on the right. The chart is widest for peole aroung 60 years old, and tapers off to nothing at age 100. The 'Female' side is slightly wider at the top than the 'Male' side.

Studying populations

Population pyramids
(a.k.a. age pyramids)

  • Ubiquitous visual tool in demography
  • Picture of the ‘shape’ of an entire population
  • Shows size of a population at different ages
  • Can compare sub-populations on right and left
    (traditionally gender binary)
Nearly symmetric chart. The vertical axis in the center is labeled age (0 to 100). The horizontal axis is labeled 'Male+ percent of total population' on the left and 'Female+ percent of total population' on the right. The chart compares Quebec to Nunavut. For Quebec, the chart is widest for people around 60 years old. For Nunavut, the chart is widest for people around 0 years old.

Demo­graphic theories

Black and white photo of a crowd of people, mainly facing in the same direction away from the camera.

Demographic theories

Global population

  • Increased from about 1.6 billion in1900 to about 6 billion in 2000
  • 7 billion in 2012
  • 8 billion in 2022
  • Continuous growth since 14th century

Source: Wikimedia Commons (multiple data sources)

Demographic theories

Malthusian theory (18th–19th century)

  • Based on Thomas Robert Malthus’ (1766–1834) ideas about the capacity of the earth for human populations
  • Food, violence, and disease create “positive checks” on population
  • Low fertility provides “preventive checks”
  • Predicted a cycle of growth and decline of human population
Photo of two Greater Kudu (a deer-like creature) locking horns

Demographic theories

Theories similar to Malthus' are common

  • Ecological theories of resource limitations
    Formal models of populations in resource-scarce environments
  • Either cyclic (as in Malthus’ theory) or predict slow decline in population growth
    “Sigmoid” or “logistic” growth
  • Still, global population continues to grow
    Though growth rate peaked in the early 1960s
Two simple, unlabeled, hand-drawn line charts. The first shows a line that goes up and down, the other shows a line that slowly increases in an 'S' or sigmoid pattern

Demographic theories

Photo. A grey-haired man leans over to help a small child walk on some grass

Demographic transition theory

  • By far the most widespread theory of population change in social sciences
  • Aims to explain the empirical observation that birth and death rates have both dropped significantly over the past few hundred years
  • Major claim:
    Changes associated with industrialization and modernization cause subsequent changes in mortality and fertility

Demographic transition in four “stages”

Demographic transition

The four stages of demographic transition theory:

Stage 1

Four stylized icons of swaddled human babies, and four stylized icons of human skulls
  • Birth and death rates are
    high, life expectancy is short
  • Minimal population growth
  • Ubiquitous throughout most of human history
    Transition out of stage 1 began in some places in the 18th century

Stage 2

Four stylized icons of swaddled human babies, and four stylized icons of human skulls. The row of four skulls fades to white, as if they are disappearing
  • Death rates begin to drop,
    life expectency begins to increase
  • Birth rates are still high
  • Population growth accelerates
  • Many current populations display this pattern
    E.g. some sub-saharan African nations

Stage 3

One stylized icona of a swaddled human baby, and one stylized icon of a human skull.
  • Birth rate begins to drop
  • Mortality rate remains low
  • Rate of population growth slows
  • Identified by significant drop in growth
    E.g. some Central American nations

Stage 4

  • Birth and death rates are
    both low
  • Balanced rates mean slow population increase, or even decreasing population size
  • Identified by low birth rate (<2.5%)
    E.g. many European and North and South American nations

Demographic transition

A line graph with two lines, one for birth rate and one for death rate, and a shaded area for population increase. The x-axis is labeled "Stage 1" through "Stage 5 (Yet to be seen)," and the y-axis is labeled "Birth rate" and "Death rate" (with values ranging from 0 to 40). The graph shows that birth rates and death rates are high in Stage 1, with a stable or slowly increasing population. In Stage 2, death rates fall rapidly, leading to rapid population increase. In Stage 3, birth rates start to fall, and population growth slows. In Stage 4, birth rates and death rates are both low, and the population falls and then stabilizes. Stage 5 is unknown, but birth rates may fall further and death rates may rise again.

Demographic transition

Theoretical mechanisms for …

Photo of a tin of sardines with the lid peeled back on a white surface

… decrease in mortality

  • Industrialization
    Increased access to food and other resources
  • Civic and scientific advances
    Sanitation, medicine, infrastructure
  • Economic modernization
Photo of a tin of sardines with the lid peeled back on a white surface

… decrease in fertility

  • Decrease in childhood mortality leads do decreased “demand” for children
    SLag in fertility and mortality transitions
  • Urbanization
    SChanging role of children in family life
  • Increases in employment and education
    Employment for women normalized, contraception widespread

Demographic change in Québec

Demography and society

  • Although demographic theories are primarily concerned with changes in population size, they are inextricably linked with theories of culture, norms, politics, and institutions.
  • Differences in social environment can explain demographic differences between places.
A line graph of Canada's and Quebec's total fertility rate between 2000 and 2015. The y-axis shows the total fertility rate, ranging from 1.45 to 1.75 children per woman. The x-axis shows the years from 2000 to 2015. There is a blue line for Canada and a green line for Quebec. The line for Canada shows a decrease in fertility rate from 1.7 to 1.45, while the line for Quebec shows a decrease from 1.7 to 1.55. Around 2006, the lines cross, meaning that since 2006 Quebec has had a higher fertility rate than Canada as a whole.

Image credit

Black and white photo of a crowd of people, mainly facing in the same direction away from the camera.

Photo by Rob Curran on Unsplash

photograph of a large group of people froma distance. They are all facing the same way.

Photo by CHUTTERSNAP on Unsplash

Nearly symmetric chart. The vertical axis in the center is labeled age (0 to 100). The horizontal axis is labeled 'Male population' on the left and 'Female population' on the right. The chart is widest for peole aroung 60 years old, and tapers off to nothing at age 100. The 'Female' side is slightly wider at the top than the 'Male' side.

Population pyramids from Statistics Canada

Illustration of a white-haired man sitting at a table. He is grinning cutting into a huge piece of meat. Behind the table a skeleton glares at him and holds a spear ready to thrust it into the man. Caption at the bottom reads 'Death and the glutton'

Image from Wellcome Collection

Photo of two Greater Kudu (a deer-like creature) locking horns

Photo by Derek Keats via Wikimedia

Photo. A grey-haired man leans over to help a small child walk on some grass

Photo by Igordoon Primus on Unsplash

stylized icon of a swaddled human baby

Baby by LUTFI GANI AL ACHMAD from Noun Project (CC BY 3.0)

stylized icon of a human skull

Skull by Alvaro Cabrera from Noun Project (CC BY 3.0)

A line graph with two lines, one for birth rate and one for death rate, and a shaded area for population increase. The x-axis is labeled "Stage 1" through "Stage 5 (Yet to be seen)," and the y-axis is labeled "Birth rate" and "Death rate" (with values ranging from 0 to 40). The graph shows that birth rates and death rates are high in Stage 1, with a stable or slowly increasing population. In Stage 2, death rates fall rapidly, leading to rapid population increase. In Stage 3, birth rates start to fall, and population growth slows. In Stage 4, birth rates and death rates are both low, and the population falls and then stabilizes. Stage 5 is unknown, but birth rates may fall further and death rates may rise again.

Max Roser, via Our World in Data

Photo of a tin of sardines with the lid peeled back on a white surface

Marco Verch via Flickr

Photo of a tin of sardines with the lid peeled back on a white surface

BruceBlaus via Wikimedia