Take 2,930 German adults who were never married and not partnered, follow them for eleven straight years, and ask them every single year how satisfied they are with their lives. That’s the design behind The Eras of Singlehood: 11-Year Longitudinal Trajectories of Never-Married Singles’ Well-Being Across Cohorts, published in Personality and Social Psychology Bulletin by Elaine Hoan, Geoff MacDonald, and Matthew D. Johnson, and covered Oct 11, 2026 by PsyPost. The finding that’ll surprise almost nobody who’s actually single and almost everybody who isn’t: about 90% of long-term never-married singles maintained consistently high, stable life satisfaction across the full eleven years. Not a dip-and-recover pattern. Not a slow decline covered up by averages. Stable. Baruch Spinoza never filled out a well-being questionnaire. But in 1677, in a book written mostly in geometric proofs, he argued that blessedness is generated from the inside and doesn’t depend on romantic partnership at all — and then he spent his own life proving it by declining the money and the marriage that were both, at various points, on offer.

The Quick Verdict

Question	What we found
What was studied?	Whether never-married singles’ life satisfaction, singlehood satisfaction, sexual satisfaction, and desire for a partner change over eleven years
Who ran it?	Elaine Hoan, Geoff MacDonald (University of Toronto), and Matthew D. Johnson
Where and when?	Personality and Social Psychology Bulletin; covered Oct 11, 2026 by PsyPost
Sample	2,930 adults from the German Family Panel, tracked 2009–2021, across three birth cohorts starting at roughly ages 18, 26, and 36
Core finding	About 90% of long-term never-married singles maintained consistently high, stable life satisfaction across all eleven years
Secondary finding	Singlehood satisfaction, sexual satisfaction, and desire for a partner varied widely between distinct trajectory groups — but overall life satisfaction stayed robust regardless
Who had the highest well-being	More educated, more extraverted, more likely employed full-time, lower in neuroticism
What Spinoza already argued	In the Ethics (1677), blessedness (beatitudo) is self-generated through understanding, not supplied by externals like a partner — and Spinoza lived it, unmarried and financially modest by choice

The Quick Version

A German study tracked 2,930 never-married adults for eleven years and found that roughly 90% stayed consistently satisfied with their lives the whole time — even though their satisfaction with being single, their sex lives, and how badly they wanted a partner varied enormously from person to person. Spinoza made the identical claim 350 years earlier: lasting contentment comes from something you generate yourself, not from an external attachment, romantic or otherwise. The data lines up with the metaphysics in a way that should unsettle anyone who’s been telling single friends that they just haven’t met the right person yet.

What the Study Actually Found

Most research on singlehood either runs for a few months or catches people at one moment and extrapolates. This one didn’t. Hoan, MacDonald, and Johnson pulled eleven consecutive years of data — 2009 to 2021 — from the German Family Panel, a large national survey, and built three birth cohorts: one starting around age 18, one around 26, one around 36. To stay in the sample, a person had to report being never-married and without a committed partner at every single one of the eleven annual waves. That’s a demanding bar. It filters out the drifting-in-and-out-of-relationships majority and isolates something closer to a genuinely long-term single population.

Using latent class growth analysis — a statistical technique for sorting people into distinct trajectory groups rather than averaging everyone into one smooth line — the researchers tracked four separate outcomes: overall life satisfaction, satisfaction with being single specifically, sexual satisfaction, and desire for a partner. The headline result sits in the first of those four. Roughly 90% of participants in each cohort landed in a trajectory class that stayed consistently above the midpoint of the life-satisfaction scale for all eleven years. Not rising. Not falling. Holding.

The other three outcomes told a messier, more interesting story. Satisfaction with singlehood itself split people into genuinely different groups — some stayed highly satisfied with being single the entire time, others sat in the middle, a minority stayed low. Sexual satisfaction and desire for a partner showed the same kind of spread: wide heterogeneity in where people started, but once a group’s trajectory was set, it tended to stay flat rather than trend toward or away from partnership over time. People who most wanted a partner at year one mostly still wanted one at year eleven. People who didn’t, mostly didn’t. The classes with the best overall well-being skewed more educated, more extraverted, more likely working full-time, and lower in neuroticism. As lead author Hoan put it to PsyPost, “even while singles face different romantic or sexual experiences, they generally remain quite satisfied with their lives over time.”

That’s the part worth sitting with: life satisfaction didn’t track the variable you’d expect it to track. A person with low desire for a partner and a person with persistently high desire for a partner could both land in the high-life-satisfaction group. Wanting a relationship and not having one didn’t automatically mean being unhappy with life as a whole.

What Did Spinoza Mean by Blessedness?

Beatitudo (Latin; Spinoza’s Ethics, Part V), usually translated “blessedness,” is the state Spinoza treats as the endpoint of his entire philosophical system: a stable, self-sustaining joy that arises from understanding — specifically, from grasping your own emotions, your place in nature, and what he calls the intellectual love of God — rather than from acquiring or attaching to anything outside yourself. Spinoza is explicit that “blessedness is not the reward of virtue, but virtue itself.” It’s not a prize you collect once other conditions are met. It’s the condition.

That distinction is the entire argument. Most of what people chase — money, status, romantic attachment — Spinoza calls inadequate because it’s externally contingent. Tie your contentment to a partner, and you’ve tied it to someone else’s choices, moods, mortality, and availability, none of which you control. Tie it to understanding — of your own mind, your emotions, your place in a causal order larger than any one relationship — and you’ve tied it to something that doesn’t require another person’s cooperation to stay intact.

Spinoza (1632–1677) wasn’t writing this from a position of comfortable detachment. He lived it under real pressure. At 23, the Amsterdam Jewish community excommunicated him — permanently, with unusually harsh language — over his views. Accounts of his life describe the community later offering to reverse the excommunication and pay him a pension if he’d show up at synagogue and keep his views to himself. He turned it down flat, reportedly saying he wouldn’t attend if the pension were ten times the size. Later, a wealthy student named Simon de Vries offered him an annual 500 florins — enough to live comfortably without working. Spinoza talked him down to 300, on the stated grounds that too much money would distract him from his philosophy. He never married. He supported himself grinding lenses and living simply in rented rooms, by choice, with offers of both financial security and social belonging sitting on the table the whole time. The man who argued blessedness doesn’t depend on externals had, repeatedly, the externals available and declined them.

Why Doesn’t Contentment Require a Partner?

1. Blessedness is generated, not received. Spinoza’s core move is treating joy as something you produce through understanding, not something delivered to you by circumstances. A partner can be a source of joy — Spinoza never denies that — but it’s not the only possible source, and it’s not a required one.
2. Externally dependent satisfaction is inherently unstable. Anything you need someone else to supply is, by definition, outside your control. Spinoza’s whole system is built around minimizing how much of your well-being rests on things that can be taken away by forces you don’t govern.
3. Self-sufficiency isn’t isolation. Spinoza had close friendships and correspondents across Europe. His argument wasn’t “need nobody.” It was “don’t locate your core stability in any one attachment you can’t control” — a distinction Diogenes made in cruder form two thousand years earlier, minimizing what he needed from the world rather than minimizing his connection to it.
4. The variation that matters is internal, not relational. For Spinoza, the differences between a contented single person and a discontented one wouldn’t be “has a partner” versus “doesn’t.” It would be the degree to which each person understands their own emotions and has stopped expecting any one external thing to complete them.

Why the Study and the Philosophy Rhyme

The connection here isn’t “a 17th-century rationalist predicted a German panel survey.” It’s narrower, and it holds up better for being narrower: Spinoza’s specific claim was that lasting contentment is produced internally and doesn’t require romantic partnership as a precondition. This study measured the modern version of exactly that claim, across eleven years and three cohorts, and found that the predicted precondition — having a partner, or even wanting one less — didn’t determine who ended up in the high-life-satisfaction group.

It connects to the solitude-versus-loneliness research covered here before: that work found the variable separating flourishing from suffering in aloneness wasn’t the aloneness itself, but what the person brought to it. This study is the partnership-specific version of the same pattern — being unpartnered for eleven straight years didn’t sentence 90% of this sample to poor well-being, because life satisfaction was never purely downstream of partnership status to begin with.

It also sits close to Spinoza’s own distinction between hilaritas and titillatio, the whole-person joy versus the localized, grasping kind. A relationship pursued because you believe it’s structurally required for contentment is closer to titillatio — a part of you reaching for something it’s been told it needs. Contentment built from understanding your own capacities, the way Spinoza describes it, is closer to hilaritas: stable, whole-person, not contingent on one input continuing to arrive on schedule.

And it rhymes with Schopenhauer’s account of desire, though the two philosophers land in different places. Schopenhauer thought wanting was close to inescapable and mostly a source of suffering. Spinoza’s version is more exact: the problem isn’t wanting a partner. Plenty of this study’s most satisfied participants still wanted one. The problem is building your sense of a worthwhile life entirely on top of a want that may or may not get met.

The Gap Spinoza Didn’t See Coming

Here’s where the comparison gets more interesting than a clean match, and it’s worth sitting with instead of smoothing over.

Spinoza’s framework treats blessedness as something close to binary in structure — you either understand your emotions and your place in nature well enough to be stable, or you don’t, and the externals that look relevant (money, partnership, status) are, properly understood, beside the point. This study found something messier: stability in overall life satisfaction coexisted with genuine, persistent variation in singlehood satisfaction, sexual satisfaction, and desire for a partner. Some of this sample were highly satisfied with being single. Some were not, and stayed not, for eleven years. Spinoza’s model has less room for a person who has correctly understood their emotions, lives a stable and contented life by any outside measure, and still, year after year, wishes they had a partner.

The data suggests life satisfaction and romantic desire aren’t actually the same axis — you can hold stable, high well-being while also holding a stable, high, unmet desire for partnership. Spinoza would likely say the desire itself isn’t the problem; tying your entire sense of a worthwhile life to its satisfaction would be. But the study makes a case his tidier framework doesn’t fully anticipate: that wanting something consistently, for over a decade, without ever treating its absence as evidence your life has failed, is itself a stable and apparently sustainable way to live. That’s a more complicated kind of contentment than pure self-sufficient blessedness, and the data says it’s common.

What This Study Doesn’t Show

Be precise about the size of this. The framing invites more confidence than the data earns.

Germany, Not Everywhere

The German Family Panel is a large, well-constructed national survey, but it’s one country with its own welfare state, social norms around singlehood, and cultural attitudes toward marriage. Whether the same 90% figure holds in a country with less social support for single adults, or stronger marriage-centered cultural pressure, is untested here.

Correlational, Not Causal

The study tracks who stays satisfied, not why. It can’t rule out a selection effect — that people who were already temperamentally stable and low in neuroticism were both more likely to stay single long-term and more likely to stay satisfied, with singlehood itself doing none of the causal work.

The Sample Tops Out in the Late 40s

The oldest cohort started around age 36 and was tracked eleven years, putting the ceiling on this data somewhere in the late 40s. What long-term singlehood looks like at 65 or 80 is a different, unanswered question.

Thin on LGBTQ+ Representation

The dataset includes a relatively small number of LGBTQ+ participants, which limits how confidently the findings generalize to that population specifically.

What Actually Follows From This

1. “You just haven’t met the right person yet” is not a safe thing to say to a contented single person. The data says a large majority of long-term never-married adults are already doing fine, by their own report, year after year. Treating their life satisfaction as provisional — waiting on a partner to make it real — isn’t supported by what this study measured.
2. Wanting a partner and being satisfied with your life aren’t opposites. Some of the most well-adjusted people in this sample still wanted a relationship. Spinoza’s point generalizes here better than his stricter language suggests: the goal isn’t eliminating desire, it’s not outsourcing your entire sense of a worthwhile life to whether that desire gets met on any particular timeline.
3. Ask what you’re actually building your stability on. Spinoza’s harder question survives the translation into 2026 data cleanly: if a relationship arrived or ended tomorrow, how much of your sense that your life is working would move with it? That’s not an argument against wanting partnership. It’s a question about what’s actually load-bearing.

Spinoza never ran a longitudinal panel study and never saw a trajectory-class model. He had a geometric proof about the nature of joy and a life that gave him every socially sanctioned reason to abandon it — a pension, a comfortable annuity, presumably the option of a conventional household — and declined all of it on the stated grounds that it would get in the way of something he valued more. Three hundred and fifty years later, a team working with eleven years of German panel data found 2,930 people living out a less dramatic version of the same bet: no spouse, no long-term partner, and for roughly nine in ten of them, a life satisfaction that held steady the entire time anyway. The claim was never that partnership doesn’t matter to anyone. It’s that it was never the precondition it’s so often assumed to be.

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This post discusses a 2026 study published in Personality and Social Psychology Bulletin and Spinoza’s Ethics (1677). The study’s findings are drawn from the German Family Panel, a sample of 2,930 adults who remained never-married and unpartnered across all eleven survey waves, and describe correlational patterns in life satisfaction, not a controlled experiment proving that singlehood causes well-being or a universal claim about singles in all cultures and age ranges.