Young Adults Are the Loneliest Age Group, but Isolation Is a Different Problem

Gallup’s 2023 global survey found that adults aged 19 to 29 report the highest rate of loneliness of any age group, 27%, against 17% among those 65 and older. Harvard’s Making Caring Common project found something similar in the United States two years earlier: 61% of young adults aged 18 to 25 reported serious loneliness, compared with 36% of adults overall. Cigna’s 2020 workplace survey found 73% of workers aged 18 to 22 reporting loneliness, and over 80% among employed Gen Z specifically. Three different instruments, three different populations, one consistent finding: young adults score highest on loneliness.

They do not score highest on isolation. That distinction is doing almost no work in the public conversation about this age group, and it should be.

Two different things that get measured as one

Isolation describes the objective structure of a person’s social contact: how many people they see, how often, whether they live alone, whether they belong to groups. Loneliness describes a subjective state, the felt gap between the connection a person has and the connection they want. The National Academies’ 2020 framing, echoed throughout the clinical literature, treats these as related but distinct constructs that require different measurement and, potentially, different intervention.

Young adults are, on average, among the least structurally isolated people in most societies. They tend to live with roommates or family, attend school or work in person, and have larger nominal social networks than older adults. Gallup’s 2023 country-level analysis makes the point explicitly: connectedness and loneliness “are not simple inverses of one another.” A 22-year-old surrounded by classmates and coworkers can report severe loneliness. A 78-year-old living alone with a small network can report none at all. Holt-Lunstad’s 2015 meta-analysis in Perspectives on Psychological Science found that social isolation, loneliness, and living alone were all independently predictive of early mortality, with odds ratios of 1.29, 1.26, and 1.32 respectively, adjusted for health status. Independent means exactly that: knowing a person’s isolation score tells you comparatively little about their loneliness score, and the reverse. A 2024 study in Scientific Reports built specifically to test how this relationship shifts across the lifespan found that the interplay between isolation and loneliness during the pandemic varied meaningfully by age group, which is a formal way of confirming what the demographic patterns already suggest: whatever is driving loneliness among 20-somethings, it is not primarily a shortage of people in the room.

What the age gap in loneliness is plausibly tracking

If young adults are not isolated in the structural sense, the leading candidates for their elevated loneliness scores point toward something else: instability of identity and life stage, the disruption of school-based social structures once formal education ends, comparison dynamics amplified by social platforms, and the sheer unfamiliarity of building an adult social network from a lower starting base of shared institutions. The American Enterprise Institute’s 2021 friendship survey adds a structural detail worth sitting with: 12% of Americans report no close friends at all, up from 3% in 1990, and the collapse has been sharpest among men, whose share reporting six or more close friends fell from 55% in 1990 to 27% by 2021. That is a friendship-quality story, not a contact-frequency story. A young adult can have a full calendar and an empty confidant list.

The Frontiers in Psychology study published this March gets closer to isolating the mechanism than most of the literature, because it asks which kinds of connection actually predicted wellbeing among college students recovering from the pandemic, rather than simply totting up contact hours. The consistent finding across that strand of work is that the quality and regularity of contact predict wellbeing better than the sheer volume of people in a network. That is consistent with a picture in which young adults have plenty of isolated contact points, classmates, coworkers, roommates, and comparatively few relationships with the depth or continuity that would register as protective.

The U.S. Surgeon General’s 2023 advisory, which put loneliness prevalence at roughly half of American adults and compared its mortality association to smoking up to 15 cigarettes a day, treats connection broadly and does not disaggregate isolation from loneliness in its headline figures. That is defensible as a public communication strategy, since “an epidemic of loneliness and isolation” is a more legible phrase than a paragraph of caveats. But it is also the mechanism by which the conflation propagates from the research literature into policy language, and from there into the design of interventions.

Why the conflation has practical costs

The BMC Public Health review of the state of the field, published in 2023, flags inconsistent measurement as one of the discipline’s central barriers to comparability. Isolation-versus-loneliness conflation is a specific version of that broader problem. If the working assumption is that young adults are lonely because they lack contact, the natural policy response is to generate more contact: more programming, more group activities, more structured events. If the accurate diagnosis is closer to a deficit in relationship depth or continuity, then adding volume without depth may not move the loneliness number at all, even if it looks like an intervention on paper.

There is a longitudinal comparison worth noting here. The JACSIS study tracking Japanese adults through 2020 and 2021 was structured to observe change over time rather than take a single cross-sectional snapshot, which matters because most of the isolation-loneliness literature is cross-sectional and therefore cannot say whether the two constructs move together or independently within the same person as circumstances change. A longitudinal design applied specifically to young adults, tracking both network structure and subjective loneliness as people move through the unstable years after formal schooling ends, does not appear in the current literature. That gap is more consequential for this age group than for older adults, where isolation is more often a stable structural feature, living alone, mobility limits, bereavement, rather than a transitional one.

What would settle the question

A study designed to separate these constructs in young adults would need three things the current literature mostly lacks: a validated isolation measure (network size, contact frequency, living arrangement) collected alongside a validated loneliness measure (the UCLA scale is standard) in the same cohort; a longitudinal design following people through the specific transition out of school-based social structure, since that is the plausible inflection point; and disaggregation by relationship type, distinguishing weak-tie contact from the kind of tie the American Enterprise Institute’s survey shows is disappearing. Absent that, the safest reading of the existing evidence is that young adults face a loneliness problem that runs ahead of their isolation problem, and that any intervention aimed at this age group should be evaluated on whether it changes felt connection, not just headcount.