Final answer:
Regions with high fertility rates often grapple with challenges that threaten childhood survival, leading families to have more children as a form of security against these risks. Urbanization and industrialization typically coincide with lowered fertility rates due to improved standards of living. However, fertility rates alone do not fully encapsulate population dynamics, as infant mortality also significantly influences these trends.
Step-by-step explanation:
High fertility rates often correlate with regions facing issues such as disease, poverty, and hunger which affect early childhood survival. Historically, in environments where there was a significant risk that children could succumb to these adversities, it was considered prudent for families to have more offspring to ensure that some would survive to adulthood and could contribute economically or provide care for elderly parents. This trend is observable during stage one of the demographic transition model, where population growth rates are small, as births and deaths are approximately equal.
Globally, countries with high fertility rates frequently struggle to provide for a growing population, leading to stress on resources. Family planning is crucial in mitigating the burden on families and helping control population growth. The link between urbanization and decreasing family size is also evident, as countries that industrialize and urbanize often experience a transition to lower fertility rates.
It is important to note that fertility rates are not solely indicative of population growth trends. Infant mortality rates play a significant role and are particularly high in regions with the highest birth rates. Conversely, regions with low infant and child mortality rates, like North America and the European Union, typically exhibit lower fertility rates.