Final answer:
Several factors, excluding political reasons, explain the decline in family size after 1820, including economic, cultural, and social influences. The demographic transition marked a shift to smaller families as a result of improved living conditions and changes in societal norms.
Step-by-step explanation:
The decline in family size after 1820 can be attributed to various factors, excluding political factors. Economic, cultural, and social factors all played significant roles in this demographic shift. Economic changes included the transition from agrarian to urban living, making children an economic liability rather than an asset. Cultural shifts saw changes in work nature affecting middle-class family sizes, as fewer children were able to contribute financially. Social influences included advancements in birth control knowledge and changes in women's roles within society and the workforce, leading to a decline in birth rates.
The demographic transition explains the process of declining birth and death rates as a result of improved living conditions and changes in societal norms. The Industrial Revolution ushered in enhanced nutrition and sanitation, leading to a rapid population increase initially. Eventually, however, as societies developed, parents had fewer children due to the economic security and education, leading to smaller family sizes. In Europe, this transition led to a shrinking workforce and adjustments in pension and health care systems due to an aging population.