MCAT Psychological Social Foundations Flashcards: 9b Demographic Transition Pyramids

What this deck covers

This deck focuses on 9b Demographic Transition Pyramids, giving you a quick way to review the definitions, rules, and examples that matter most for MCAT Psychological Social Foundations.

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Work through these flashcards in short sessions. Try to answer each prompt before flipping the card, then revisit any cards you miss until the explanation feels automatic.

Flashcard 1: Which demographic transition stage is defined by falling birth rate with low death rate?

Answer: Stage $3$ (industrial/late industrial). Birth rates decline to match already-low death rates.

Flashcard 2: Which DTM stage best matches: low death rate, falling birth rate, and continued but slowing growth?

Answer: Stage 3. Classic Stage 3 pattern: mortality transition complete, fertility declining.

Flashcard 3: Calculate RNI if $\text{CBR} = 30$ per $1000$ and $\text{CDR} = 10$ per $1000$ (ignore migration).

Answer: $20$ per $1000$ per year (about $2.0\%$ per year). RNI = $30 - 10 = 20$ per $1000$ (divide by $10$ for percent).

Flashcard 4: Identify the most likely cause of a sudden notch affecting mainly males in one adult age cohort.

Answer: War or sex-specific mortality concentrated in that cohort. Wars disproportionately kill young adult males.

Flashcard 5: Which DTM stage typically has the highest rate of natural increase (RNI)?

Answer: Stage 2. Maximum gap between births and deaths occurs in early transition.

Flashcard 6: What is the demographic transition model (DTM) intended to describe about a country over time?

Answer: Shifts in birth and death rates as a country industrializes. DTM tracks how population dynamics change with industrialization.

Flashcard 7: What defines DTM Stage 1 (high stationary) in terms of birth and death rates?

Answer: High birth rate and high death rate; minimal net growth. Pre-industrial societies have high mortality offsetting high fertility.

Flashcard 8: What defines DTM Stage 2 (early expanding) in terms of birth and death rates?

Answer: High birth rate with rapidly declining death rate; rapid growth. Better sanitation/medicine drops deaths while births stay high.

Flashcard 9: What is the approximate replacement-level fertility in developed countries?

Answer: About $2.1$ births per woman. Accounts for infant mortality; exactly $2.0$ would mean decline.

Flashcard 10: What is demographic momentum in the context of population growth?

Answer: Continued growth after fertility drops due to a young age structure. Large youth cohorts ensure growth even at replacement fertility.

Flashcard 11: What defines DTM Stage 3 (late expanding) in terms of birth and death rates?

Answer: Declining birth rate with low death rate; slowing growth. Urbanization and education reduce fertility as mortality stays low.

Flashcard 12: What is the dependency ratio intended to capture about a population?

Answer: Burden on working-age group from young and old dependents. Ratio of non-working ages to working-age population.

Flashcard 13: What is a population pyramid and what two variables does it display?

Answer: Age distribution by sex, usually as horizontal bars by cohort. Males left, females right; width shows cohort size.

Flashcard 14: Which population pyramid shape indicates rapid growth and high fertility (expansive, stationary, or constrictive)?

Answer: Expansive (broad base, narrow top). Wide base from high fertility; narrows due to mortality.

Flashcard 15: Which population pyramid shape indicates an aging population with low fertility (expansive, stationary, or constrictive)?

Answer: Constrictive (narrow base, relatively wider middle/older cohorts). Low fertility creates smaller young cohorts than older ones.

Flashcard 16: Identify the most likely interpretation of a large bulge in ages $15$–$24$ on a population pyramid.

Answer: A past baby boom or cohort effect entering young adulthood. Echo effect from high births $15$-$24$ years ago.

Flashcard 17: What defines DTM Stage 4 (low stationary) in terms of birth and death rates?

Answer: Low birth rate and low death rate; stable or slow growth. Post-industrial equilibrium with both rates at low levels.

Flashcard 18: What is commonly meant by DTM Stage 5 in terms of population change?

Answer: Birth rate falls below death rate; population decline. Some developed nations see fertility drop below replacement.

Flashcard 19: What does total fertility rate (TFR) measure in a population?

Answer: Average number of children born per woman over her lifetime. TFR estimates completed fertility for a synthetic cohort.

Flashcard 20: What is the formula for population growth rate when net migration is included?

Answer: $\text{Growth rate} = (\text{CBR} - \text{CDR}) + \text{NMR}$. Total growth includes natural increase plus net migration rate.

Flashcard 21: What is the formula for rate of natural increase (RNI) when migration is ignored?

Answer: $\text{RNI} = \text{CBR} - \text{CDR}$. Natural increase equals crude birth rate minus crude death rate.

Flashcard 22: Which population pyramid shape indicates slow or zero growth with similar cohort sizes?

Answer: Stationary (more rectangular). Equal-sized cohorts indicate stable birth and death rates.

Flashcard 23: Which demographic transition stage is defined by falling death rate with high birth rate?

Answer: Stage $2$ (transitional/early industrial). Death rates drop first, creating rapid population growth.

Flashcard 24: Which demographic transition stage has low birth rate and low death rate with stable population?

Answer: Stage $4$ (postindustrial). Both rates stabilize at low levels, growth near zero.

Flashcard 25: Which demographic transition stage is often described as very low birth rate causing decline?

Answer: Stage $5$ (population decline). Birth rate falls below death rate, causing negative growth.

Flashcard 26: In the DTM, what social changes commonly contribute to the birth-rate drop in Stage $3$?

Answer: Contraception, female education/employment, urbanization, lower infant mortality. These factors reduce desired family size and enable family planning.

Flashcard 27: What is a population pyramid designed to display about a population at a given time?

Answer: Age distribution by sex (typically in $5$-year cohorts). Shows population structure with males on left, females on right.

Flashcard 28: Which population pyramid shape indicates rapid growth with a large youth cohort?

Answer: Expansive (wide base, narrow top). Triangle shape indicates high birth rates and young population.

Flashcard 29: In the DTM, what key change most directly drives the death-rate drop in Stage $2$?

Answer: Improved sanitation, nutrition, and medical/public health measures. These improvements reduce disease and increase survival rates.

Flashcard 30: Which population pyramid shape indicates population decline with fewer young people than middle-aged?

Answer: Constrictive (narrow base, larger middle/older cohorts). Inverted shape shows declining births and aging population.