The Best of Whoever's Nearby: How We Actually Choose Who to Love

Almost everyone I know met their partner by accident. They shared a stairwell in halls, or a commute, or a desk at work. A friend's wedding sat them at the same table. None of them set out to find a soulmate among the eight billion of us. Ask how it happened, though, and the word that comes back is always fate.

I think fate is doing a lot of lifting there. The plainer story is duller and, once you look at it, much better supported. We don't search for the best possible person. We take the best of the few that circumstance puts in front of us. The pool is small, we mostly didn't assemble it, and we choose from inside it. "The one" is a label we add later, because an accident is easier to carry once it looks like a plan.

People have been picking at this for most of a century, and the findings are not subtle.

Proximity does most of the work

Start with the dullest variable available: how far apart two people live.

In 1932 a sociologist named James Bossard went through five thousand marriage licences in Philadelphia and measured the distance between the two addresses on each one. The curve was steep and a little embarrassing. Marriages dropped off fast as the distance grew, and roughly a third of couples had been living within five blocks of each other. Bossard made a rule of it, and someone later gave the rule a better line than it deserved: Cupid's wings are best suited for short flights.

That was a city before cars, so maybe it doesn't carry. But the tidier version of the finding turned up later, inside a single building. Leon Festinger and two colleagues studied married-student housing at MIT where flats were handed out in whatever order people came up the waiting list, which made neighbours essentially strangers dealt at random. Then they asked who had become friends with whom. The answers followed the corridor. Forty-one per cent of people named the person next door as a friend. Two doors along, twenty-two. At the far end of the same short hallway, ten. These were not judgments of character. People had befriended whoever they passed on the way to the stairs.

What mattered, Festinger said, was functional distance: not the metres between two doors but how often the layout of a place throws people together. Newer research has nibbled at the details and left the core alone. Living closer stops helping past about a quarter of a kilometre, and inside an office the urge to talk to someone fades to almost nothing within a few desks. The exact number drifts from study to study. The shape of it never does. Long before compatibility or chemistry or any of the qualities we flatter ourselves by selecting for, geography has drawn up the guest list.

We warm to whatever we see often

Underneath proximity sits a second mechanism, and it is even less flattering. Being near someone doesn't only give you the chance to like them. It tilts you toward liking them, reason or no reason.

Psychologists call it the mere-exposure effect, and it's one of the sturdier things they've found: across hundreds of experiments, showing people something more often makes them like it more, with no content required. Faces, words, shapes, invented syllables. The cleanest demonstration I've read plays out like a quiet prank. In 1992 two researchers sent four women who looked broadly alike into a large lecture course and had each attend a different number of times, none or five or ten or fifteen, under one instruction: speak to no one. At the end of term the class was shown photographs of all four. The students couldn't say who they were and had never traded a word with them, yet they rated the ones who had turned up more often as better looking and more likeable. Attendance alone moved the needle.

So the machine runs like this. Proximity sets a few faces in front of you over and over, and repetition does the quiet rest, turning the person who is simply always there into the person you catch yourself thinking about. It isn't bottomless. Push exposure too far and it can sour, and familiarity reliably raises how much you like someone more than how attractive you find them. The direction holds regardless, and it ought to bother anyone who pictures themselves as a discerning judge of other people.

The shortlist was drawn before you looked

Those few faces had also been filtered, well before you arrived, by something larger than any building.

Sociologists have a name for the people you'll seriously weigh as partners: your field of eligibles. It's the band of humanity that your upbringing, class, schooling, language and faith have already marked as plausible. You didn't deliberate over it. It came attached to your postcode and your parents. (The neat mid-century theories that imagined courtship as a chain of separate filters fell apart when people tried to reproduce them, so I'd hold the mechanism loosely. The broad idea is solid.)

You can read the filter straight off the people we end up marrying. The largest recent study of how alike couples are pooled close to two hundred datasets and found that partners match most on the things a shared world simply hands them: politics, religion, years of schooling, whether they drink or smoke, all correlating around a half. On personality, the inner stuff we claim to prize most, they barely match at all.

Sit with that gap for a moment, because it turns the romance inside out. We are not, in the main, combing the species for the temperament that slots into ours. We pair with people who look like us, vote like us, pray or don't like us. With, that is, whoever our particular corner of the world got around to introducing.

Nobody optimises

Say you wanted to do it properly anyway, to find not just a good partner but the best one open to you. There's a maths for that. The secretary problem tells you how to pick the top candidate from a queue you can only pass through once: watch the first 37 per cent, commit to nobody, then take the next person who beats everyone you've seen. Elegant.

Nobody runs their love life this way.

What people do instead has its own name, and it won the man who described it a Nobel. Herbert Simon's satisficing is a word stitched from satisfy and suffice. His point was that once the options outrun what a mind can hold side by side, we give up on the best, set a bar, and take the first thing over it. Optimising, he wrote, is "virtually always unrealizable in real life." And settling is not even the weaker move. When researchers simulated people hunting for a mate, the blunt good-enough rules did as well as the clever 37-per-cent one, and now and then better.

On the rare occasion life does hand us a wider field, we don't rise to it. At speed-dating events, thousands of snap yes-or-no decisions deep, more options made people less choosy rather than more. Faced with a long line to clear, they leaned on what you can size up in three seconds, height and weight, and stopped weighing the things that take a conversation to learn. A bigger menu made people faster and cruder, not choosier.

Stack those up and my friends' fate looks a good deal more ordinary. Chance gathers a small pool, pre-sorted for people like them. Proximity and repetition warm them to the faces inside it. And instead of searching, they satisfice, taking the best of what's good enough among whoever was actually around. For almost all of history, for almost everyone, "looking for the one" has been a story narrated over the top of exactly that.

The internet broke the geography

That's where I'd have stopped, except that the picture really did shift, and recently enough that most of us watched it move.

For most of the last century every common way of meeting was a version of proximity. Family. Neighbours. Church. School. Work. For about sixty years after the war the biggest single channel was friends introducing friends. Each of those is a way of meeting someone already close to you.

Then dating went online, and the numbers out of Stanford leave little room for argument. Meeting through a screen climbed from near zero in the early nineties to the most common way American couples form at all: about thirty-nine per cent of straight couples, and roughly sixty-five per cent of same-sex ones, who got together in 2017. The shape of it is the real news. Online dating strips out the go-betweens. The friends and relatives who used to handle introductions thin to almost nothing, the share of online couples with any mutual tie dropping below four per cent, and close to nine in ten beginning as outright strangers. People had started pairing with someone their existing world would never have walked them up to. The little circle Bossard sketched in 1932, the one that had penned in just about everyone before, was for a lot of people simply gone.

It mattered most where proximity had served people worst. If the supply of plausible partners within walking distance was thin, because you're gay, or past forty, or just somewhere with few options, the apps didn't only widen the door. They cut one into a wall. I'll say this straight, since it works against my own argument: if the claim is that nearness boxes us in, then for a large and growing number of people the box has opened.

But a bigger pool is still a pool

Look, though, at what actually grew.

A larger pool is still a pool. An app exists to land you in a room with someone eventually, which puts the distance limit quietly back. And the instant people begin choosing, the old sorting clicks into place. Online daters still pair off along the same seams of race, class, age and education as ever. The app hands you a longer shortlist, and it is still a shortlist, screened now by your own thumb and an algorithm's guesswork rather than by your parish or your dorm. Same engine, new casing.

Underneath sits a flatter disappointment. The apps never really sold more people. They sold better matching, the optimiser's dream finally made good by data, and that part hasn't shown up. The most careful review of the research found no published evidence that any matching algorithm can predict who will actually click, and warned that scrolling endless profiles can start to make other people feel swappable and harder to commit to. (The popular dread that too much choice freezes us is, for what it's worth, shakier than people assume; across studies the effect more or less cancels out.) The modest verdict holds: no one has shown that a wider net brings in better love.

You may have run into the opposite claim. A much-quoted 2013 paper reported that couples who met online were slightly happier and slightly less likely to divorce. It helps to know the survey was paid for by eHarmony, that its lead author advised the company for money, and that the difference was minuscule in any case. A later, independent study found it pointing the other way. The unglamorous read from the literature is that how you met your partner barely forecasts how things go. The door widened. What happens once you are through it has not.

A smaller, better question

It's tempting to take all this as a demotion, as if a partner who was the best of a small accidental pool, rather than a soulmate sieved from billions, must be worth a little less. I've come round to the opposite.

The one is a quietly cruel idea. It plants a single right answer somewhere in the eight billion and leaves every actual relationship looking provisional beside it, shadowed by some better-matched person you were statistically bound to miss. The research clears that ghost out of the room. There was no grand search to fail. There was a particular set of people your life brought near; you chose one of them, you went on choosing them, and then the two of you started the slow unphotogenic work of growing into a fit, which arrives after the choice and not before it.

So the question worth asking was never the unanswerable one, whether someone better is out there. It's the smaller one that actually has an answer. Is this good, given who was ever really in the room? Cupid's wings are short. The longer I look at the evidence, the more that reads to me like mercy than like a limit.