Population growth occurred because the death rate decreased while the birth rate remained high. This imbalance led to a significant increase in population.
Key Factors Contributing to Population Growth
The provided reference highlights a critical period where:
- Death rates declined: Various factors contributed to fewer deaths, such as advancements in medicine, improved sanitation, and better nutrition.
- Birth rates remained constant: For a significant period, families continued to have a large number of children.
- Delayed decline in birth rates: It wasn't until late in the 19th century that married couples, in substantial numbers, started consciously reducing the number of children they had. This shift happened earlier in some countries and later in others.
How These Factors Interacted
The combination of a declining death rate and a constant birth rate created a "population boom." Here’s how:
- More people surviving infancy and childhood: Fewer people died young, meaning a larger proportion of each generation reached reproductive age.
- High birth rates ensured large families: As birth rates remained high, the number of births continued to outpace deaths, causing populations to grow rapidly.
The Shift in Family Size
The reference also points out that eventually, the situation changed:
- Late 19th-century reduction in family size: Married couples, increasingly in large numbers, started having fewer children. This shift was a major turning point in population trends.
Example
Imagine a community where previously 10 out of 20 children died before adulthood, resulting in a population barely growing. Then, improvements cause the death rate to drop to 2 out of 20, but birth rates stay the same. This leads to a big increase in the adult population because of increased survival rates and sustained high birth rates.
