Some Americans aren’t feeling particularly happy, and their household size might be part of the reason. According to the 2025 World Happiness Report released last week, an individual’s well-being and life satisfaction are closely linked to the number of people they live with.
In regions where larger households are more common — such as Mexico and Costa Rica — life satisfaction tends to be higher, with household size playing a key role in happiness. Even in Europe, where solo living is more prevalent, researchers observed that people in bigger households generally report greater well-being.
So, what’s the magic number for happiness at home? Based on data from Mexico, Colombia and several European countries, four to five household members is the sweet spot for maximum connection, support and overall life satisfaction.
In contrast, worldwide, those who live alone or in households with six or more members report lower life satisfaction, which is likely linked to economic factors.
“A household of four or five often comes with a built-in network of emotional and practical support,” said Spencer James, a professor in the School of Family Life at Brigham Young University, in an email. “While it can be busy, many hands can share responsibilities, lighten each other’s load, and foster a sense of team spirit.”
In a world where social isolation is on the rise, these findings suggest that who you live with — and how many people are under your roof —might matter more than we think.
The shrinking household
This year, Americans reported the lowest level of happiness than ever before, ranking 24th among 147 countries, falling behind Canada, Mexico and Israel, according to the report. Researchers attribute this drop to increasing social isolation, a weakening sense of community and fewer shared meals.
But the structure of American households plays a key role too in shaping well-being — both individually and collectively.
“Households are relational spaces — a community of caring and sharing — where members create strong interpersonal relationships that contribute to their life satisfaction,” the report authors wrote.
In the U.S., these relational spaces are shrinking. While the country’s population has grown, household sizes have steadily declined. In 2024, about 35% of all U.S. households consisted of just two people, compared to 29% in 1970.
The number of Americans living alone has more than tripled since 1940, according to United States Census Bureau data, a trend fueled by declining birth rates. As fewer people opt to have children, the number of couples in the U.S. without kids (25%) now surpasses those with children (24%). Out of all states, Utah has the largest average household size of 2.99 people, according to 2021 Census data, compared to 2.5 nationally.
This demographic shift is not unique to the United States. Global fertility has dropped from 4.84 children per woman in 1950 to 2.23 in 2021, according to the happiness report. In many developing nations, single-parent households are on the rise, while multigenerational living is becoming more common, with parents, children and even grandchildren sharing a home. Meanwhile, household size remains a major predictor of happiness worldwide. In Mexico, nearly half of households consist of four or more people, compared to just 24% in Europe.
Relational and economic benefits at odds
The World Happiness Report also highlights the well-being cost of living alone. In Europe, single-person households have an average life satisfaction score of 6.6, compared to 7.5 for those in five-member households. Despite Mexico’s lower economic standing, its larger households result in stronger social ties, which may help explain why Latin American countries often report higher well-being than their GDP per capita would suggest.
In Mexico, authors of the report observed lower life satisfaction among single-parent households, but only if there are no other family members. Even in single-parent households, other family members can “mitigate the wellbeing cost” if they are under one roof. While those in single and single-parent households report higher economic satisfaction, their satisfaction remains low in family and personal connections.
Economic factors play a role, too. As household size increases, so does economic dissatisfaction. Single-person households report higher levels of economic satisfaction, the researchers found. But they also report decreased satisfaction with interpersonal relationships. “If economic satisfaction is prioritized, then a small household size offers advantages,” the report said. “However, people are much more than mere consumers and their human relationships play a central role in their lives and their wellbeing.”
As the structure of households continues to evolve, the question looms: Are modern living arrangements optimizing for financial stability at the cost of human connection?
Why living with others matters
The report looked at happiness through the lens of a “shared joy and caring experienced within relationships.” As a social unit, family shapes prosocial behavior, the report said, since that’s where interpersonal relationships first develop before extending to broader civic engagement and charitable activities.
But putting more people into one living space doesn’t automatically result in well-being, the report noted. The quality of interactions matters. “Thus, the time spent together as a family, along with positive emotional exchanges, affective bonds, genuine interest, communication, and mutual support largely accounts for the positive link between household size and life satisfaction,” the report said.
In fact, often it’s living with others that incentivizes a proactive approach to forming stronger bonds, according to Catherine Pakaluk, a social scientist and economics professor at the Catholic University of America, and the author of “Hannah’s Children: The Women Quietly Defying the Birth Dearth.”
For many women she interviewed for her book — most of them religious — the belief that family relationships extend beyond this life made them more willing to make “relationship-specific investments” in those they live with — and that often translates into stronger and more satisfying relationships. This applies to children, spouses and extended families. “You come to see the sense and value in that person, which becomes enhanced by the willingness to make those investments in the quality of the relationship,” Pakaluk told me.
Although the authors of the World Happiness Report view two to three children as a “sweet spot” for family happiness, some see an even larger family as a richer and more practical way to live. A big family incentivizes parents to delegate responsibilities to older kids and adopt a less intense parenting style, according to Timothy Carney, a senior fellow at the American Enterprise Institute and a father of six.
“The best way to make parenting and childhood happier and less stressful is to have more kids, not fewer of them,” Carney, the author of “Family Unfriendly: How Our Culture Made Raising Kids Much Harder Than It Needs To Be,” wrote for The Washington Post. He cites a 2018 survey, in which the mothers’ stress increased with each child up until number three, where mothers of four reported less stress.
The collaboration of a larger family creates a “family-centric” ethos — as opposed to child- or parent-centric — where each person brings a valuable contribution and has a role to play.
With a larger domestic network, more people can meet your needs, according to Pakaluk. “Each person feels that they have more people to meet their needs, but also each person feels needed by other people,” she said. “And that also contributes to happiness.”
Is the happiness research sound?
Historically, larger families were the norm, with 77% favoring three or more children in 1945, according to Gallup. However, preferences shifted in the late 1960s and 1970s due to concerns about overpopulation and economic factors, leading to a decline in birth rates.
Preferences for smaller families peaked in 1986, and recently support for larger families has been rising, reaching its highest level since 1971, according to the 2023 Gallup data. Americans are now nearly evenly split on whether smaller or larger families are preferable: 47% of Americans prefer smaller families (one or two children), according to Gallup, while 45% favor larger families (three or more children). Twelve percent lean toward four children and only 2% would go for five or more children.
Pakaluk and others have noted the limitations of cross-sectional studies, particularly in assessing economic stress and life satisfaction in different households. Since these kinds of studies do not track the same individuals over time, they don’t account for how financial capacity and stress levels evolve as people age. This can lead to misleading correlations, much like how surveying 20-year-olds might falsely suggest that being in college predicts poverty, despite its long-term economic benefits, she told me.
While household size may be correlated with overall family well-being, it doesn’t guarantee happiness.
“Cultural norms, economic resources, personal temperaments, and extended support networks play significant roles,” BYU’s Spencer James said. “Some families find four or five people to be their ‘sweet spot,’ while others thrive in different configurations.”