Half of Adults or Sixty-One Percent? Two Loneliness Surveys, Two Different Numbers

Two figures circulate as the headline statistic on American loneliness. Cigna’s 2020 workplace report put the share of U.S. adults who report feeling lonely “sometimes” or “always” at 61%. The U.S. Surgeon General’s May 2023 advisory, Our Epidemic of Loneliness and Isolation, cites a figure closer to half of U.S. adults. Both are frequently quoted as if they describe the same thing. They do not.

The 11-percentage-point gap is not noise, and it is not evidence that one source is wrong. It is a product of three separate choices each study made: which instrument it used, which population it sampled, and when it collected its data. Each of those choices moved the number in a specific, traceable direction.

What Cigna actually measured

Cigna’s 2020 report, Loneliness and the Workplace, surveyed U.S. adults using items built around a proprietary loneliness index rather than a validated academic scale such as the UCLA Loneliness Scale. The 61% figure represents adults who reported feeling lonely “sometimes or always” — a threshold that captures anyone with even intermittent loneliness, not only those experiencing it as a chronic or dominant state. The report also frames its findings partly through a workplace lens: it reports that 73% of workers aged 18 to 22 and more than 80% of employed Gen Z respondents describe themselves as lonely, and that lonely workers miss work roughly twice as often for illness and five times as often for stress-related reasons.

That workplace framing matters. A sample drawn through or oriented toward employed adults skews younger and more urban than the general adult population, and younger adults consistently report higher loneliness than older ones in nearly every dataset that measures the two groups separately. The Harvard Graduate School of Education’s Making Caring Common survey, published the following year, found 61% of young adults aged 18 to 25 reporting serious loneliness against 36% of Americans overall — the same instrument-independent pattern of youth skewing the aggregate upward.

Cigna’s 61% figure also reflects data collected before the COVID-19 pandemic reached the United States; the report was published in January 2020. It is sometimes cited today as though it describes pandemic-era isolation. It does not. It describes a baseline that, if anything, understates what many surveys found once lockdowns began.

What the Surgeon General’s advisory drew on

The Surgeon General’s 2023 advisory does not report a single new survey. It synthesizes existing research, and its “approximately half” figure functions as a summary statement across multiple sources measured with different instruments at different points in time — not a single clean estimate from one fielded questionnaire. The advisory’s more consequential number is not the prevalence figure at all but its mortality comparison: it states that the health risk associated with social disconnection is comparable to smoking up to 15 cigarettes a day, a framing drawn from the mortality meta-analyses that predate the advisory itself rather than from prevalence surveys.

This is a case where the headline percentage is doing less analytical work than the source intends. The advisory’s real contribution is the six-pillar national strategy it proposes, not a new prevalence estimate. Treating “about half” as a precise, comparable figure to Cigna’s 61% mistakes a policy synthesis for a survey result.

Where a validated instrument lands

The AARP Foundation’s 2018 survey of adults 45 and older offers a useful calibration point precisely because it used the 20-item UCLA Loneliness Scale rather than a bespoke set of items. Among that older population, it found one in three adults — 33% — met its loneliness threshold. That is roughly half of Cigna’s 61% figure, drawn from a comparable general-population sampling logic but restricted to an older age band and using an instrument with decades of academic validation behind it.

The AARP survey also identified network size and diversity, and physical isolation, as the strongest predictors, and found a striking gradient by neighborly contact: 33% of respondents who had spoken with their neighbors were lonely, against 61% of those who never had. That 61% figure — coincidentally identical to Cigna’s national headline number — belongs to an entirely different subgroup and an entirely different question. It describes the loneliest slice of a specific behavioral category among older adults, not the U.S. adult population as a whole. Citing it alongside Cigna’s 61% as though they corroborate each other would be an error, even though the digits match.

Three variables, one number

Lay the three surveys side by side and the pattern is not subtle. Broader thresholds (“sometimes or always” feeling lonely, as Cigna asked) produce higher numbers than instruments requiring a pattern of chronic loneliness. Younger, employment-linked samples produce higher numbers than samples weighted toward older adults. And pre-pandemic snapshots, collected in Cigna’s case in January 2020, cannot be read as describing conditions after March 2020, even when a report is republished or cited years later.

The BMC Public Health review of the loneliness research field, published in June 2023, names this directly: inconsistent measurement across studies is one of the central barriers to comparing findings, and the field has not converged on a shared instrument the way, for instance, depression research has converged on a small number of validated scales. Loneliness prevalence figures are not fungible across studies in the way that, say, unemployment rate figures are across different government releases using a common definition. Each figure is only interpretable against the specific instrument, population, and moment that produced it.

What follows from taking the gap seriously

None of this means either the Cigna or Surgeon General figure is unreliable on its own terms. Cigna’s number is a defensible answer to a specific question — how many U.S. workers report at least occasional loneliness — asked at a specific moment. The Surgeon General’s advisory is a defensible synthesis for the purpose it serves, which is building the case for federal policy attention, not pinning down a precise national rate.

The mistake is treating either as the number for American loneliness, as though a single figure could summarize a condition that varies this much by age, by instrument, and by year. A reader who needs a genuinely comparable time series would do better looking at studies that reuse the same validated instrument across multiple waves — something closer to what the UCLA scale enables when applied consistently, as in the AARP survey — than at a set of one-off reports that each built their own measure.

A stronger evidence base would field the same validated instrument, at regular intervals, across a nationally representative sample stratified by age, and report loneliness and isolation as separate constructs rather than folding both into a single “connection” index. Until that exists, prevalence figures for American loneliness should be read the way this pair should be read: as answers to different questions, not competing answers to the same one.