The Demographic Transition

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Objective

Students will be able to describe the causes and effects of populations going through the "demographic transition".

Big Idea

As economic and educational opportunities increase, the populations of developing nations go through somewhat predictable stages of growth and affect the environment in different ways.

Introduction

This lesson is the final teacher-centered lesson of this unit and is actually more of a review and organization of many of the ideas that came up throughout the unit.  This lesson focuses on the so called "demographic transition", or the predictable pattern of population change as societies move from pre-industrial to post-industrial economies.   

 

The lesson essentially consists of two parts:

1. A pre-class textbook reading and homework assignment focused on close reading techniques, critical-thinking questions, and content vocabulary development.

2. An in class presentation that provides supplementary examples to review the concepts and vocabulary from the chapter along with a class discussion seeking to draw students into more critical examination of the topic at hand and assist in their ability to connect the concepts to their personal experiences. 

The textbook reading comes from Environmental Science: Your World, Your Turn by Jay Withgott.

If you do not have that particular textbook, I would recommend finding a similar chapter or chapters and modifying the lesson accordingly.  

Alternately, the powerpoint attached to the Direct Instruction section covers most of the same concepts and vocabulary as the chapter.  If you have a shorter class period, you may want to skip the reading assignment and assign the discussion questions as homework.  You could then hold the class discussion on the following day.       

In my case, I assign the textbook reading on the meeting previous to this lesson.  In that way, students will have already covered the concepts on their own and the powerpoint presentation will be less of a lecture and more of an opportunity for students to ask questions and clarify their understanding. 

Connection to Standard:

In this lesson, students will prepare for class by reading and determining the central idea of a text, establish familiarity with relevant scientific vocabulary, and then draw evidence from the text to support arguments and opinions presented as part of their participation in a group discussion.  

 

Direct Instruction

20 minutes

Like I mentioned above, I assign the textbook reading as a homework assignment to be completed upon arrival to this class period.  The powerpoint presentation is then more of a review and an opportunity for students to ask questions.  

 

Wondering WHY I use lectures as a pedagogical strategy?  Watch this video.

Wondering HOW I use the Powerpoint to differentiate instruction? Watch this video.

Wondering why I choose to have a reading assignment AND a lecture on the same content?  Read this rationale.

Wondering how you might use this lesson's resources if you don't plan on presenting a lecture? Read this reflection.

 

When class begins, I ask students to get their homework out and first give them about 10 minutes to discuss the critical thinking questions with their group members.  During this time, I walk around and put a stamp on completed homework and answer any questions that students bring up.  If students bring up a good question or insightful comment, I ask them to please remember to bring that up in the larger class discussion to follow the presentation.  

Affording this time before the presentation allows students to "field test" their answers with a smaller group, increasing their confidence to participate in the larger discussion.  Also, because the discussion is graded by groups, it allows the ideas of individual members to influence the thinking of their peers which may lead to greater insights or even new questions.  Finally, while I walk around, I listen to the nature of student discussions and get a better sense of what kinds of questions may be floating around the room, allowing me to emphasize certain aspects of the lesson or offer more detailed examples to scaffold the instruction.

After I have stamped all the homework assignments, I distribute the note sheet that accompanies the presentation.  As I've mentioned in previous lessons, offering students a note sheet provides a readymade study guide for later and allows students to focus on their thoughts and the concepts being discussed as opposed to focusing all of their attention on copying down copies amounts of notes.   

 

Please Note: I find it important to really do thorough checks for understanding on a few points:

1. On slides 6 and 7 which regard the difference between developing an developed nations, I use the map on those slides to ask students to pick out examples of countries in both the (blue toned) developed and (red toned) developing categories.  If you like, you can use this as a call back to the age structure diagram lesson when the students selected countries based on being youthful, transitional, or mature.  If that worksheet is handy, students could identify their countries in each category and see what their corresponding status is on this map. 

Another interesting thing to ask on this slide is to ask what trends students see in this map.  One possible trend they could mention that is readily apparent is that the more developed nations (excepting Australia) are in the Northern hemisphere, while less developed nations tend to be in the Southern hemisphere.  They might also point out that the least developed nations are found predominantly in Africa and Southeast Asia.

2. If you really focus on the map aspect of the developed/developing countries, you can look at the fertility rate map on slide 9 and ask students to see what trends they see here.  Although it is not so evenly split between North and South, students can probably still see that African nations have much higher fertility rates on average.  This sets up discussion of what it really means to be developed in terms of infrastructure and education (which are explicitly presented on slides 18 and 19).

3. On slides 12-15 where the stages of the demographic transition are explained, each slide contains a graph of the entire demographic transition.  When the graph appears after the information has been presented on a particular slide, I ask students to point out what is happening on the graph with birth rates, death rates, and population growth.  For example, after we discuss that a transitional society often maintains high birth rates due to entrenched cultural attitudes about family size even though their death rates have dropped due to industrialization, we look at the graph together and I ask students to identify the birth rate line and ask what it's doing (it's fluctuating, but high), and again with the death rate (it's dropping quickly), and finally, what effect these factors have on the population (it's growing very quickly).  I would repeat this with each slide to make sure students can really see how these factors affect the growth of populations.

 

Discussion

30 minutes

Following the presentation, I let students know that we will wrap up by having a class discussion to review the concepts of the lesson.  Again, depending on your class length, it may be preferable to have this follow-up discussion on the following day.  

The discussion protocol for this lesson:

  1. all groups are required to participate in the discussion and will receive a “participation” grade for the day

  2. groups with more than one member that participate will receive a higher participation grade

  3. groups that participate more frequently will receive a higher grade

 

These criteria make the group collectively responsible for their grade and accountable to each other. If no one in the group participates, the group as a whole will receive a failing grade.  If only one member of the group participates, regardless of how often, the group can’t receive any grade higher than a C.  

 

To keep track of participation, I begin by making a map of the class with the group tables labeled by group name.  Since there are four students at each table, as a student from a particular group participates, I make a tally mark in the position of that student in their group.  In this way, I can tally how often the group participates, which members are participating, and how often.  To determine "average" participation, I add up all tally marks and divide by the number of groups, rounding down.  I then use this rubric to determine their participation grades.

 

If you'd prefer to not give a grade for participation in discussions, see this reflection where I discuss the conditions that arose that allowed me to not to grade for participation but still have meaningful discussions with broad participation. 

 

See this discussion guide for a more detailed explanation of how to lead this particular discussion, but I would bring the following to your attention as key points in the discussion:

1. On the question regarding how the benefits of industrialization (sanitation, medical technology, and agriculture) have affected population growth in industrialized (and above) nations, the original question asked for students to choose just one factor and describe its effect on populations.  It's important to discuss all three factors, so in the case that any factor was not answered as homework, you might want to specifically mention that factor and have students discuss in small groups for a minute to consider its effects before sharing out.  Here are the basics of what I hope students understand about each factor:

  • Sanitation: clean water and hygienic conditions have affected the transmission of certain diseases and reduced mortality rates and increase life expectancy.
  • Medical technology: antibiotics, vaccines, sterile instruments and environments, and advances in surgical techniques have extended life spans and reduced mortality rates.
  • Agriculture: industrial agriculture has allowed populations to grow because it has increased the amount of food available and thereby raised the human carrying capacity of the environment which has allowed high birth rates to not be culled by starvation due to scarce or inconsistent food supplies.

 

2. On the question of which stage of the demographic transition the U.S. is currently in, answers will vary depending on the perspective of your students.  This connects well with the much more personal final question about students’ own family sizes.  Reasonable answers to this could be that the U.S. is probably in the post-industrial stage due to our modern infrastructure and wide access to medical technology and economic and educational opportunities for women.  Another possibility would be to argue that we are in the industrial stage because while death rates are almost universally low (there are of course tragic exceptions to this in underserved communities), birth rates remain high amongst some groups.  Some astute students of mine pointed out that an influx of immigrants with a transitional mindset (i.e., their high birth rates have not yet declined) balance out a more established “first world” population in the post-industrial stage (with low birth rates) and the U.S. is left at an average of the industrial stage, though it is not uniform.