One Home, One Car, One of Everything: How Households Came Apart
Personal, Interpersonal & Societal
Now
A species built to share
Humans did not evolve to get through life alone, or even in pairs. Anthropologists describe us as “cooperative breeders”: children survived because people besides their mothers helped raise them. A review of 45 studies of populations without modern contraception found that in almost every one, at least one relative besides the mother improved a child’s chances of survival, with maternal grandmothers helping most consistently (Sear & Mace, 2008). Across 32 present-day foraging societies, bands averaged about 28 adults, and most band members were not close relatives of one another (Hill et al., Science, 2011). The ancestral human household was a community of relatives, in-laws and friends.
The need has not gone away. A meta-analysis of 148 studies covering 308,849 people found that stronger social relationships were associated with about 50% higher odds of survival, an effect comparable to quitting smoking (Holt-Lunstad et al., 2010). The World Health Organization’s Commission on Social Connection links loneliness to more than 871,000 deaths a year. These studies are observational, but the pattern is consistent and large.
From nearly six people to two and a half
In 1790 the average American household held nearly six people. By 2025 it held 2.50. People living alone made up 13.1% of US households in 1960 and 29.5% in 2025 — 39.7 million one-person households. In the mid-1800s about seven in ten Americans over 65 lived with an adult child; by 2000, fewer than one in seven did (Ruggles, 2007). The same shift has happened across wealthy countries; in Finland, Denmark, Germany and Japan, living alone is even more common than in the United States. Most of the American decline happened between 1960 and 1990; household size has changed little since.
More households, more sales
Every separate household needs its own rent or mortgage, utility connections, appliances, often a car, and its own subscriptions. Official statistics build this in. The equivalence scale used across the EU and by the OECD assumes that two adults sharing a home need about one and a half times the income of one person living alone, not twice as much. Put the other way round, two people living apart spend about a third more, together, for the same standard of living. The environmental footprint follows the same arithmetic: in the EU, people living alone have the highest per-person carbon footprint, about 9.2 tonnes of CO2-equivalent a year, roughly double that of people in households of five or more (Ivanova & Büchs, 2020). In the world’s biodiversity-hotspot countries, households multiplied faster than people between 1985 and 2000; had household size stayed the same, there would have been 155 million fewer households to build, heat and furnish by 2000 (Liu et al., Nature, 2003).
In a market economy, each additional separate household is additional revenue for landlords, lenders, builders, utilities, carmakers and retailers. In the United States, the separate single-family home was also actively promoted. From 1917 the National Association of Real Estate Boards, working with the US Department of Labor, ran an “Own Your Own Home” campaign that borrowed wartime propaganda techniques; in the 1920s Commerce Secretary Herbert Hoover expanded it into a partnership between government and the housing industry (Hutchison, Journal of Policy History). From the 1930s, federal mortgage underwriting through the Federal Housing Administration steered lending toward new suburban single-family houses, and away from older city neighbourhoods and Black families through redlining (Jackson, Crabgrass Frontier, 1985).
Rules that penalise sharing
Some laws still make shared living harder. In the areas covered by the National Zoning Atlas, about 81% of residentially zoned land allows only single-family housing; in California the average is 77.8%. On most of that land, adding a second home for a grandparent or a grown child has long been restricted or prohibited; when California loosened its rules, permits for such units rose from 1,336 in 2016 to 26,924 in 2023.
In 1974 the US Supreme Court upheld a village ordinance that allowed any number of relatives to share a house but no more than two unrelated people (Village of Belle Terre v. Boraas); many towns still cap unrelated housemates. Three years later the Court struck down a city ordinance under which a grandmother, Inez Moore, had been convicted and sentenced to five days in jail and a $25 fine for living with her son and two grandsons who were cousins rather than brothers (Moore v. City of East Cleveland, 1977).
Benefit rules can penalise sharing too. When an older or disabled person receiving US Supplemental Security Income lives in someone else’s household and gets shelter there, the payment can be reduced by up to about a third; a 2024 rule stopped counting food, but shelter still counts. Two married SSI recipients receive at most $1,491 a month in 2026, against $1,988 for two single recipients — a penalty for marrying of $497 a month. In the UK, Universal Credit deducts £96.55 a month from housing support for each adult “non-dependant”, such as a grown son or daughter, living with the claimant, even if they pay little or nothing towards the rent.
Company terms, which are contracts rather than laws, follow the same logic. Netflix tells subscribers they may not share an account outside their household; after its 2023 crackdown it added 13.1 million subscribers in a single quarter. Such rules do not punish living together. They make each household a separate paying unit, so a grandparent across town pays again.
Two economies under one roof
Even the closest bond is increasingly run as two separate economic units. The share of US married couples with no joint bank account rose from 15% in 1996 to 23% in 2023, while those with all accounts joint fell from 53% to 40% (Census Bureau). In a 2026 Bankrate survey of married and cohabiting couples, 26% kept their money completely separate, including about half of Gen Z couples against 15% of baby boomers, a gap that partly reflects life stage. Many have good reasons: later marriage, second families, protection from a partner’s debts or financial control. Still, in a randomised study, engaged and newlywed couples assigned to open a joint account kept their relationship quality steady over two years, while couples who kept separate accounts showed the usual decline (Olson et al., 2023).
Less time together
Between 2003 and 2020, Americans’ in-person time with friends fell from about 60 minutes a day to about 20; for people aged 15 to 24, from about 150 minutes to 40 (US Surgeon General, 2023). The share of Americans who say they have no close friends rose from 3% in 1990 to 12% in 2021. Whether people feel lonelier is debated: there has been no measurable rise among older adults, and a modest rise among young adults. Contact itself has clearly declined.
The return of shared living is mostly about money
Multigenerational living has partly come back. The share of Americans living in such homes fell to 12% in 1980 and had risen to 18%, or 59.7 million people, by 2021. Asked why, people most often name money: 40% say financial issues are a major reason, and 67% a major or minor one; among adults aged 25 to 39 living with their parents, 57% say finances are a major reason. In July 2020, as pandemic job losses spread, 52% of Americans aged 18 to 29 lived with a parent, higher than at the end of the Great Depression. In 2025, 49% of adults under 30 lived with a parent, up from 37% in 2019 (Federal Reserve).
Meanwhile a record 22.7 million US renter households (49%) spent more than 30% of their income on housing in 2024, and Harvard’s Joint Center for Housing Studies reports that many young adults “cannot afford to form new households, instead doubling up or living with family.” Researchers estimate that about 3.7 million Americans were doubled up in 2019 — staying with relatives or friends because of economic hardship or the loss of a home — a situation many advocates and researchers now count as a form of homelessness.
Money is not the only reason. A third of people in multigenerational homes cite caregiving, 28% say it is how their family has always lived, immigration has played a part, and most describe the experience as positive; one Pew analysis found that across metro areas in 2023 the share of young adults living at home did not vary with local rents. But the overall picture is clear: the partial return of shared living has been driven largely by financial pressure, not by a broad revival of chosen community. People are pushed apart while they can pay for separate homes, and pushed back together when they cannot.
After
In the Transition, where you live and with whom becomes a choice made for its own sake. Homes, food, healthcare, transport and the materials for a good life are open to everyone, at no cost, with no pressure. No one has to move back in with their parents because rent has outrun wages, and no one has to stay apart because sharing a home would mean losing support. Nobody profits from multiplying households, so nothing is pushing people to split into the smallest possible units, and no rule docks anyone’s share because a grandparent, a disabled adult child or a friend moves in.
That opens up a wider range of ways to live. A grandmother can have her own small home on her daughter’s land, close enough to share meals, far enough to close her own door. Friends can share a large house. Neighbours can build cohousing, the arrangement first tried at Sættedammen in Denmark in 1972, where every household keeps its own private home around a common house with a shared kitchen, garden and play space. Chosen families, single parents, and people who simply prefer living alone are all treated as fully legitimate. The recurring pattern that works in practice is “near, not necessarily with”: close enough for daily help, with real privacy.
Much of what every household now buys separately can be shared at the neighbourhood level: tool libraries, repair workshops, laundries, guest rooms for visiting family, workshop and studio space, and a pool of shared vehicles that are there when needed instead of sitting idle in hundreds of driveways. Germany already runs more than 500 multigenerational community houses where children, parents and elders meet, help each other and share skills. Connection becomes a design goal, alongside safety and durability: walkable neighbourhoods, places to sit and talk, and care for children and elders spread across many hands, as it was for most of human history.
Privacy and individual agency are protected, not traded away. No one is assigned to a household, required to share, or pressured to live communally. Everyone keeps a private space with a door that locks, and leaving an arrangement is always possible. The real gains of the last century are kept: women’s and young people’s independence, the freedom to leave a controlling family, the right to live differently from one’s parents. Because no one depends on another person for food or shelter, a shared home can never become a financial trap, and money can no longer be used as a tool of control within a couple. The old question of joint or separate accounts simply disappears. What partners share is time, a home, and the decisions they make together.
Shared living still has real trade-offs. People living close together disagree about noise, chores, guests and habits, and some need more solitude than others. Good shared living depends on good norms: clear agreements made in advance, fair rotation of household work, accessible mediation, and protected private space. The end of monetary extraction does not end physical limits: land, materials and energy are finite, and decisions about how many homes to build, of what size and where, still have to be made openly within ecological limits. During the transition, existing zoning and benefit rules apply until they are democratically changed, and people can begin with what is within reach: a tool library, a shared garden, a standing Sunday meal (see Culture and the Transition for starting points in different settings, and Human Nature for the evidence on cooperation).
What really drives fragmentation
Market incentives, and the laws they helped shape, push toward separate units and profit from each one. But that is not the whole story. Households have shrunk in almost every country as incomes rose, including welfare states and non-Western societies; a study of 78 countries over 51 years found that individualist practices, including living alone, rose most consistently with socioeconomic development (Santos, Varnum & Grossmann, 2017). People often choose privacy when they can afford it. Wage work freed young adults from waiting to inherit the family farm, which historian Steven Ruggles sees as a main reason elders stopped living with their children. Many people living alone are widowed older adults. Pensions and welfare states made independence possible; Swedish policy deliberately set out to release individuals from dependence on family and charity. In north-western Europe, small nuclear households were common centuries before industrial capitalism. No evidence was found that businesses set out to break up families; what is documented is an incentive, active promotion of the single-family home, and rules that penalise some kinds of sharing. The market reliably rewards fragmentation; it is one powerful force among several, and it amplifies the others.
Individualism and collectivism
Individualism, the cultural emphasis on personal autonomy, choice and self-expression, carries real strengths, including more innovation (Gorodnichenko & Roland) and less pressure to conform. Both ends of the spectrum carry costs. At the individualist extreme, isolation grows and acting together becomes harder: US counties with a longer frontier history show more “rugged individualism” and more opposition to redistribution today (Bazzi, Fiszbein & Gebresilasse, 2020), and during COVID-19 they saw less social distancing and mask use. At the collectivist or rule-tight extreme, cultures gain order and coordination but show less tolerance of deviance and dissent (Gelfand et al., 2011), and very strong family ties go with fewer opportunities for women and young people outside the home (Alesina & Giuliano, 2010).
The Nordic countries show that the choice is not between the two extremes. Denmark and Sweden are among the most individualist societies on current cultural-dimension scores, and many people there live alone, yet they combine that autonomy with high social trust and union membership of around two-thirds of workers. The problem is not individualism as such. It is isolation combined with market pressure, where people are left to provide everything for themselves without shared institutions to fall back on. The aim is to keep personal freedom while making it easy and normal to share.