West Visayas State University/2020
NCSI 111 (People and the Earth’s Ecosystem)
Lesson 3: Population Pyramid: The shape of the society’s
population [Week 3]
Introduction
Two of the most common variables necessary in the study of population
dynamics are age and sex of individuals within a given area.
Population Reference Bureau (2019) stated that age-sex structure is the
composition of a population as determined by the number or proportion of males and
females in each category.
These data on age-sex structure are used to construct population pyramid,
which is one of the most visual representation of the population. The resulting
shape of the graph can tell much about what is happening in the population (SDSU,
Census Data Center, 2020)
The population pyramid, also known as the age-sex pyramid, is a “snapshot”
of a population in time. It shows how the population are distributed among age and
sex categories (Khan Academy, 2020).
This population pyramid takes various shapes. The types of population
pyramid, as well as its interpretation will be learned in the succeeding pages of this
module.
PRIOR TO THE LESSON
Pre-Assessment
Write TRUE if the statement is correct and FALSE if otherwise in the space
provided before each item..
_____ 1. Age and sex data are not given importance in the study of
population dynamics.
_____ 2. The shape of the population pyramid defines the future of the
population.
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Manajero, Angeles, Banquillo, Monroy, & Verzo
West Visayas State University/2020
NCSI 111 (People and the Earth’s Ecosystem)
_____ 3. A constrictive population pyramid has broad base and narrow top.
_____ 4. An expansive population has high birth rates as well as high
death rates.
_____ 5. Developing nations would take the shape of a stationary pyramid.
Feedback
Check if you have previous knowledge about the next lesson.
1. FALSE
2. TRUE
3. FALSE
4. TRUE
5. FALSE
Review
Write the letter of your answer in the space provided before each item.
_____ 1. It is the variability of the spread of the population in the entire country.
a) density c) age-sex structure
b) distribution d) birth rate
_____ 2. Which among parameters can determine the growth or
decline of the population?
a) Deaths and emigration c)deaths only
b) Births and immigration d) births only
_____ 3. The total population divided by the total land area.
a) Fertility rate c) birth rate
b) Density d) distribution
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Manajero, Angeles, Banquillo, Monroy, & Verzo
West Visayas State University/2020
NCSI 111 (People and the Earth’s Ecosystem)
_____ 4. Which among the choices is a not directly influenced by age and sex?
a) mortality c) fertility
b) migration d) distribution
_____ 5. Which of the choices is a physical factor that contributes to the
uneven distribution of the population on Earth?
a) Political b) economic c) social d) climate
Motivation
How do you think can age and sex affect the labor force in a population?
Why?
_______________________________________________________________
_______________________________________________________________
NEW LESSON
Age-Sex Structure
Age-sex structure refers to the number of individuals of sex and age group in
the population. The numbers of males and females in young, middle, and older age
groups determine how fast a population grows or declines. It is represented by a
special type of graph called population pyramid.
Types of population pyramids
Population pyramid tells us of the shape of the population. Bezy (2016)
mentioned that population pyramid is a graphical representation of the age and sex
composition of the population. On the other hand, Preshoff (2014) said that
population pyramids are not only powerful predictors of the future, but it gives us a
record of the past. Furthermore, it may also provide insights about political and
social stability, and economic development of a population (Wakim & Grewal, 2020).
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Manajero, Angeles, Banquillo, Monroy, & Verzo
West Visayas State University/2020
NCSI 111 (People and the Earth’s Ecosystem)
Boucher (2016) discussed the three types of population pyramids, namely:
expansive, constrictive, and stationary.
1. Expansive
Expansive population pyramid is used to
describe populations that are young and
growing.
They are often characterized by their
typical ‘pyramid’ shape, which has a broad
base and narrow top.
Expansive population pyramids show a
larger percentage of the population in the
younger age cohorts, usually with each age
cohort smaller in size than the one below it.
These types of populations are
typically representative of developing
nations, whose populations often have high fertility rates and lower than average life
expectancies.
2. Constrictive
Constrictive population pyramid is used to
describe populations that are elderly and
shrinking.
It can often be seen like beehives and
typically have an inverted shape with the
graph tapering in at the bottom.
It represents a smaller percentages of
people in the younger age cohorts and are
typically characteristic of countries with higher
levels of social and economic development,
where access to quality education and health
care is available to a large portion of the
population.
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Manajero, Angeles, Banquillo, Monroy, & Verzo
West Visayas State University/2020
NCSI 111 (People and the Earth’s Ecosystem)
3. Stationary
Stationary or near stationary population
pyramid is used to describe a population that
is not growing.
They are characterized by their rectangular
shape, displaying somewhat equal
percentages across age cohorts that taper off
toward the top.
These pyramids are often characteristic of
developed nations, where birth rates are low
and overall quality of life is high.
Interpretation of Population Pyramids of
some countries
Wakim & Grewal (2020) provided examples of the population pyramids of
some countries and its interpretation.
The population
pyramid of Nigeria (2015)
has a broad base of young
children and tapered sides
showing rapidly decreasing
numbers of people at older
ages. This represents an
expansive population.
This reflects a
population that has a high
birth rates and relatively
high death rates. Nigeria
is typically a developing
nation that has very high
fertility rate and has an overall low quality of life.
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Manajero, Angeles, Banquillo, Monroy, & Verzo
West Visayas State University/2020
NCSI 111 (People and the Earth’s Ecosystem)
This next graph is
owned by France (2015),
showing a narrow base of
children and young adults,
reflects relatively low birth
rate over the past several
decades.
There is a bulge of
people in mid-to-adulthood,
an evidence of higher birth
rates in previous generations
(the post-World II baby
boom) coupled with low death
rates.
Also, there is a larger proportion of females than males at older ages, which
is especially pronounced, that it is due to the higher rates of death of males than
females.
The last example
that will be presented
here is the population
pyramid of Egypt (2010).
The 2010 population
pyramid of Egypt has a
youth bulge in the young
adult age groups.
The “Youth Bulge”
shown in the graph
depicts a
disproportionately large
cohort of young adults, in
which this age groups typically enter the labor force and electorate. Thus, the social,
political, and economic implications are, there will be high rates of unemployment, as
well as social and political alienation. These conditions, in turn, may result in a
heightened risk of violence and political instability.
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Manajero, Angeles, Banquillo, Monroy, & Verzo
West Visayas State University/2020
NCSI 111 (People and the Earth’s Ecosystem)
A youth bulge has been posited as an important contributor to the rise of fascism
in the 20th century Europe, the spread of communism during the Cold War, and the
events of the Arab Spring, which began in Egypt in 2011.
If you would like to know more about Arab Spring you may browse through this
link: https://www.history.com/topics/middle-east/arab-spring
At this point, now that you already know how to interpret the different types of
population pyramid, you may now proceed to the next activity.
Activity
Activity 3.1
Before starting off with this activity, please view the video in the link given
below, to give you an overall understanding of the population pyramids and its
interpretation.https://www.youtube.com/watch?time_continue=7&v=RLmKfXwWQtE
&feature=emblogo
If you do not have connectivity, you may look for the video in the USB
provided to you.
If you are done viewing the video, you may now perform the activity.
Make a population pyramid using the Philippines’ population data given
below. Properly label your graph. Interpret it in terms of births, deaths, political,
economic, social, and cultural conditions of the Philippines’ population for the year
2018. The guide questions below may help you analyze your population pyramid.
1. What is the shape of the population pyramid?
2. What information or unique scenario that can be taken from
the graph?
3. Can you briefly discuss the birth and death rates of the
population using the graph?
4. What are the implications of such scenario in the political,
economic, social, and even cultural conditions of the population?
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Manajero, Angeles, Banquillo, Monroy, & Verzo
West Visayas State University/2020
NCSI 111 (People and the Earth’s Ecosystem)
Below is the date of the age and sex structure of the Philippines in 2018.
Age Group Male Female Age Group Male Female
0-4 years 5,875,800 5,555,500 44-49 2,832,400 2,780,800
5-9 5,646,200 5,368,700 50-54 2,465,500 2,453,000
10-14 5,379,500 5,105,400 55-59 2,012,100 2,055,200
15-19 5,253,000 4941,400 60-64 1,531,000 1,633,900
20-24 5,067,100 4,825,200 65-69 1,055,400 1,213,400
25-29 4,599,100 4,448,800 70-74 652,300 842,300
30-34 3,979,700 3,889,900 75-79 373,200 554,400
35-39 3,543,200 3,474,400 80 + 315,000 567,800
40-44 3,192,300 3,115,700
Feedback
Consider this Rubric in rating your output in this activity (Activity 3.1).
Score 10 6 2
Criteria
Pyramid Graph Plotted the graph Plotted the graph Plotted the graph
accurately with accurately inaccurately
complete label and
neatly drawn
Conceptual Discussion is mainly Discussion is based Discussion is based
Discussion of the based on important on scientific on personal opinions
answer to the scientific concepts concepts and only.
questions discussed in this personal opinions.
lesson.
Sentence Structure Sentence effectively Sentence effectively Repeated errors in
structured with no structured with 1-2 Sentence structure
grammatical, minor errors in with more than 2
spelling, grammar, spelling, errors in grammar,
capitalization, and capitalization, and spelling,
punctuation errors. punctuations. capitalization, and
punctuations.
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Manajero, Angeles, Banquillo, Monroy, & Verzo
West Visayas State University/2020
NCSI 111 (People and the Earth’s Ecosystem)
SUBSEQUENT TO THE LESSON
Summary
Age-sex structure refers to the number of individuals of sex and age group in
the population. It is represented by a special type of graph called population
pyramid.
There are three types of pyramidal graph namely: Expansive, Constrictive,
and Stationary.
The type of pyramidal graph may reveal the economic, political, and cultural
conditions of the population.
Reflection
At this juncture, you may now consider applying what you’ve learned in this
lesson. You may answer the following questions.
1. Can you possibly make a population pyramid using the age-sex structure
of your barangay/town?
____________________________________________________________
____________________________________________________________
2. If so, why do you think it is important to study the population pyramid of
your barangay/town?
____________________________________________________________
____________________________________________________________
How will this help you understand the current condition and the future of
your barangay/town?
____________________________________________________________
____________________________________________________________
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Manajero, Angeles, Banquillo, Monroy, & Verzo
West Visayas State University/2020
NCSI 111 (People and the Earth’s Ecosystem)
Post-Assessment
Make your own matrix of the three types of population pyramids showing the
following parameters: a) Shape & its Description b) Characteristics in terms Age &
Sex Structure c) Implications categorized as to social, political, & economic.
Feedback
Maximum Score 6 4 6
Type of Pyramid Identified the Discussed the Identfied and
pyramid(2pts), characteristics of discussed specific,
drawn the shape the pyramid in relevant, and
with complete terms of age and important
labels(2pts), and sex structure implications to the
described it thoroughly and population, at least
correctly(2pts). concisely for every one for each
age group(2pts) category
and sex (2pts/category).
group(2pts).
Population Pyramid 1
Population Pyramid 2
Population Pyramid 3
References
Bezy, J. M. (2016, April 7). Population Pyramid. Retrieved from:
https://www.britannica.com/topic/population-pyramid
Boucher, L. (2016). What are the different types of population pyramids?
Population Education: A program of population connections. Retrieved
from: https://populationeducation.org/what-are-different-types-population-
pyramids/
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Manajero, Angeles, Banquillo, Monroy, & Verzo
West Visayas State University/2020
NCSI 111 (People and the Earth’s Ecosystem)
Population Reference Bureau (2019, August 14. Glossary of Demographic
Terms. Retrieved form: https://www.prb.org/glossary/
Preshoff, K. (2014, May 5). Population pyramids: Powerful predictors of the
Future [Video file]. Retrieved from:
https://www.youtube.com/watch?time_continue=7&v=RLmKfXwWQtE&featur
e=emb_logo
Census Data Center, South Dakota State University (2020). Age and Sex
Structure. Retrieved from: https://www.sdstate.edu/sociology-rural-
studies/census-data-center/age-and-sex-structure
Khan Academy (2020). List tables, survivorship, and age-sex structure.
Retrieved from:
https://www.khanacademy.org/science/biology/ecology/population-
ecology/a/life-tables-survivorship-age-sex-structure
Wakim, S. & Grewal, M. (2020, June 6). Introduction to human populations.
Retrieved from:
https://bio.libretexts.org/Courses/Monterey_Peninsula_College/MPC_Environ
mental_Science/04%3A_Populations/4.01%3A_Introduction_to_Human_Popu
lations
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