4.2.2 - Birth Rates, Death Rates and Family Size

Measuring demographic change

Demography is the study of population size, structure and change. For sociologists, demographic trends are never just numbers: they reflect shifts in gender relations, class inequality, health, culture and state policy. Since 1900 the UK has moved from a society with relatively high birth and death rates to one with much lower rates on both sides. Migration also affects population size, but the key families-and-households story here is that people have fewer children and live longer.

A few terms help us read this pattern accurately. The birth rate is the number of live births per 1,000 of the population each year. The death rate is the number of deaths per 1,000 population each year. The infant mortality rate measures deaths under age one per 1,000 live births. Natural change is the gap between births and deaths; if births exceed deaths, population grows without needing migration. Net migration is the balance between immigration and emigration, although it is not the main focus of this lesson.

The long-term pattern is clear. Birth rates have trended downwards, even though there were baby booms after the Second World War and again in the 1960s. Fertility fell below replacement level in the later twentieth century. Smaller completed families became more common than in the Victorian period, although period fertility and completed family size are different measures. Death rates have also fallen sharply over the long run, especially infant mortality. That combination matters: when fewer babies die and adults live longer, the age structure of society changes and so do household forms.

Explaining falling birth rates

Sociologists explain falling fertility as a product of social change rather than simple personal preference. Harper argues that the most important change is women's altered social position. Greater access to education means many women spend longer in full-time study. Expanded employment opportunities make paid work, income and career progression more realistic alternatives to early motherhood. Reliable contraception, especially the pill, increases control over fertility. Feminism has also weakened the idea that a woman's identity should be centred on marriage and childbearing.

Economic and cultural changes reinforce this shift. In industrial and post-industrial society, children are usually an economic cost rather than an economic asset. They stay in education for longer, cannot legally contribute labour to the household in the old way, and are raised in a more child-centred culture where parents feel pressure to invest heavily in each child. Smaller families therefore make sense both financially and emotionally.

Beck and Beck-Gernsheim connect falling fertility to individualisation. In late modern society, people are encouraged to build biographies through choice, lifestyle and self-development. Parenthood becomes one option among many rather than a compulsory life stage. This helps explain delayed first births, smaller families and the rise of the child-free lifestyle. However, sociologists would add that "choice" is structured by class, housing costs, insecure work and gender expectations, so individualisation is not the whole story.

Declining infant mortality also helped drive fertility down. In the past, high infant death rates encouraged larger families because parents could not assume every child would survive. As healthcare, sanitation and nutrition improved, parents no longer needed to have many births to achieve the family size they wanted. In that sense, falling birth rates and falling death rates are linked.

Why death rates fell

The fall in death rates is another long-term social change with major family consequences. McKeown argued that the decisive cause of falling mortality in the nineteenth and early twentieth centuries was improved nutrition. Better diets increased resistance to infectious disease, and much of the mortality decline began before modern medicine could offer highly effective treatments. This is a powerful argument because it focuses attention on living standards, not just hospitals.

McKeown's thesis is useful but incomplete. It tends to understate the importance of clean water, sewerage, improved housing, vaccination, antibiotics and later the NHS. Public health measures and welfare provision reduced exposure to disease, while medical advances became increasingly important once infectious diseases could be prevented or treated more effectively. The strongest sociological conclusion is therefore multi-causal: mortality fell because nutrition, sanitation, medicine and state welfare worked together over time.