A leading family researcher has warned that Britain has become “dangerously complacent” about the scale of family breakdown.
Dr Harry Benson, Research Director at the Marriage Foundation, said the latest official data on families and households pointed to a “profound social change” that had received little public attention despite long-term consequences for family stability and child wellbeing.
He said that seemingly stable household figures released by the Office for National Statistics (ONS) mask a far deeper social crisis affecting children and parents across the country.
While the figures show only modest changes in household composition over the past decade, Dr Benson worries about the growing number of children who are no longer living with both of their natural parents.
“Nearly half of all teenagers are no longer living with both natural parents,” he said, describing the trend as roughly five times the level seen during his own childhood in the 1970s.
According to the ONS, married households with dependent children increased moderately from 59% in 2015 to 61% in 2025, while cohabiting households fell marginally from 16% to 15%.
The proportion among couple households with dependent children who were married stayed stable at 79%, while cohabiting couples reduced minimally from 21% to 19%.
The ONS also recorded a rise in civil partnerships, particularly following the legalisation of opposite-sex civil partnerships in 2019, with civil partner couples increasing from 0.1% to 1.4% over the past decade.
Lone-parent households also declined minimally from 25% to 23% over the same period.
However, Dr Benson argued that these headline figures create the impression that family life in Britain has remained broadly stable when, in reality, many children continue to experience parental separation and instability.
Dr Benson highlighted that the long-term decline of marriage remains one of the central but often overlooked drivers behind weakening family stability.
While divorce rates among married couples have dropped significantly in recent decades, he said family breakdown remains far more common among unmarried relationships, particularly cohabiting couples.
“The human cost is immense: broken relationships, broken dreams, and poorer outcomes for many adults and children alike,” Dr Benson said.
He also warned of growing financial pressures linked to family breakdown, particularly for parents raising children alone.
Earlier analysis by the Marriage Foundation and the Deaton Poverty Review indicated that official household categories can understate the extent of family disruption experienced by children, particularly among unmarried couples.
The ONS figures show that married couples still make up the majority of UK families, accounting for 65.3% of all families in 2025, although this has fallen slightly from 66.6 per cent a decade earlier.
Cohabiting couples represented 17.6 per cent of families, while lone-parent families accounted for 16%, with the data also showing a modest rise in same-sex cohabiting couples over the past decade.
The data also highlighted broader demographic trends affecting family life.
Around 29 million households now exist across the UK, with nearly 30% consisting of people living alone. Almost 50% of those living alone are over the age of 65.
Meanwhile, more young adults are continuing to live with their parents into later adulthood, particularly men.
The proportion of adults between the ages of 20 to 34 living at home rose from 25.4% in 2015 to 28.7% in 2025, with one in three men now residing with their parents.
The ONS suggested rising housing costs and delayed life milestones may be contributing factors behind the trend.
Dr Benson said new research from his recently completed PhD at the University of Bristol, due to be released jointly by Marriage Foundation and the Centre for Social Justice next month, would provide further evidence about the relationship between marriage and long-term family stability.
He said the findings challenge some earlier assumptions in social policy research and offer “robust new evidence” that marriage plays a greater role in protecting family stability than much of the existing research has argued.
