For centuries, love stories have repeated one powerful idea: somewhere in the world there is one person meant especially for you.
One person who will understand you differently from everyone else. One person whose arrival will somehow make the confusing parts of life fall into place. One person you were always supposed to meet.
We call that person a soulmate.
It is a beautiful idea. It has inspired poems, songs, films, marriages, prayers, and probably more than a few questionable dating decisions.
But is it actually true?
Do human beings really have one and only one soulmate for an entire lifetime? Or can we potentially build an extraordinary life with more than one person? Could someone lose the love of their life and later genuinely fall in love again without making the first love any less real?
Psychology cannot prove whether souls exist or whether God, fate or the universe assigns particular people to each other. Those are philosophical or spiritual questions. What science can examine, however, is something more testable: how people think about romantic destiny, how compatibility works, what predicts successful relationships, and whether the idea that there must be exactly one perfect partner makes mathematical or logical sense.
When those pieces are put together, an interesting answer emerges.
There is currently no scientific evidence showing that every human being has exactly one predetermined romantic soulmate. In fact, psychology, mathematics and ordinary human experience make the possibility of multiple highly compatible partners much easier to defend.
But that does not mean the word soulmate is meaningless.
It may simply mean we have been defining it the wrong way.
The first problem: What exactly is a soulmate?
Before asking whether there is only one soulmate, we have to decide what the word means.
People use it in very different ways.
For one person, a soulmate means:
“The only person on Earth I was destined to marry.”
For someone else, it means:
“Someone with whom I have unusually deep emotional compatibility.”
Another person may use it for someone who understands them exceptionally well.
Some religious people may understand a soulmate as a person brought into their life by God.
Others may believe there can be romantic soulmates, friendship soulmates and even several soulmates at different periods of life.
These definitions matter because they make completely different claims.
If a soulmate simply means someone with whom you can develop an unusually loving, intimate and meaningful relationship, there is no logical requirement that only one such person can exist.
But if a soulmate is defined as the one person in existence supernaturally assigned to you, then science has a different problem: that claim is almost impossible to test.
Science can study attraction, commitment, compatibility, communication and relationship satisfaction. It cannot currently conduct an experiment that detects whether two people’s souls were cosmically assigned to one another.
So we need to separate two questions:
Can science prove that exactly one soulmate exists? No.
Can science investigate whether people appear capable of forming exceptionally deep bonds with more than one possible partner? Yes.
That second question becomes much more interesting.
Many people believe in soulmates, but not necessarily only one
The soulmate idea is far from rare.
A 2015 YouGov survey of 1,000 American adults found that 69% said they believed there was such a thing as a soulmate, while 18% said no and 13% were unsure. Interestingly, responses became more complicated when participants were asked whether a person has only one soulmate or can have more than one. In the complete sample, 25% selected only one soulmate, while 33% selected more than one. (ygo-assets-websites-editorial-emea.yougov.net)
An earlier Pew Research Center survey asked Americans more directly whether every person has only one true love. Only 28% agreed, while 69% disagreed. Among the people who believed in one true love, 79% said they had already found theirs. (pewresearch.org)
These surveys should not be treated as global scientific proof. They involved Americans, and they are now relatively old. Cultural and religious beliefs about love vary considerably.
Still, they reveal something important.
Even among people who believe deeply in romantic love, there is no universal agreement that love must involve exactly one possible person.
That disagreement also exists in psychology.
Psychology has actually studied the “soulmate mindset”
Psychologists often use a more precise term than soulmate belief.
They call it destiny belief.
Psychologist C. Raymond Knee’s influential work distinguished between two broad ways people can think about relationships.
The first is destiny belief:
Two people are either meant for one another or they are not.
The second is growth belief:
Good relationships are developed, strengthened and maintained through effort.
Knee’s research found that people holding strong destiny beliefs tended to treat compatibility as something relatively fixed. When relationships encountered difficulty, they could be more inclined to interpret that difficulty as evidence that the relationship was simply not meant to be. Growth-oriented people were more inclined to see difficulties as problems that could potentially be worked through (Knee, 1998). (paperzz.com)
That distinction has survived decades of subsequent relationship research.
A major longitudinal study published in the European Journal of Personality examined 904 couples over two years.
Researchers found something fascinating.
People with stronger destiny beliefs tended initially to report greater relationship satisfaction. In other words, believing “this is my person” can accompany very strong feelings about a partner.
But people with stronger growth beliefs experienced a slower decline in relationship satisfaction over time.
Growth beliefs were also associated with believing that relationship satisfaction had improved in the past and would continue improving in the future (Gander et al., 2025). (journals.sagepub.com)
That finding does not mean destiny beliefs are automatically bad.
Nor does it prove that soulmates do not exist.
It suggests something subtler:
Feeling that someone is “the one” can be powerful. But believing that love must also be developed may be especially useful once real life begins.
Because real relationships eventually contain tired mornings, financial decisions, disagreements, changing bodies, relatives, career problems, misunderstandings and days when nobody feels as romantic as they did during the first six months.
The dangerous version of the soulmate idea
There is a romantic version of soulmate belief:
“Out of everyone I could have loved, I choose you.”
And there is a potentially destructive version:
“If you were really my soulmate, this relationship would never be difficult.”
Those are not the same philosophy.
Research reviewed by Gander and colleagues suggests that people with stronger destiny beliefs may sometimes interpret conflict as evidence of incompatibility, while growth beliefs tend to encourage communication and problem-solving. (journals.sagepub.com)
However, the evidence deserves nuance. In studies conducted in the United Kingdom and Hungary, Zagefka and Bahul (2021) found that destiny beliefs themselves were not consistently associated with poorer relationship satisfaction. A stronger problem was the belief that disagreement between partners was inherently destructive. (journals.sagepub.com)
So science does not support the simplistic message:
“Believing in soulmates ruins relationships.”
The better conclusion is that problems can arise when soulmate belief creates unrealistic expectations.
For example:
“If we argue, we aren’t meant for each other.”
“My soulmate should automatically know what I need.”
“If I feel attracted to somebody else, I must have married the wrong person.”
“If this relationship requires effort, it cannot be true love.”
Those conclusions do not logically follow from love.
What actually predicts a good relationship?
This is where modern relationship research becomes particularly revealing.
One of the largest projects of its kind combined 43 longitudinal studies involving 11,196 romantic couples and used machine-learning methods to investigate what predicts relationship quality.
The strongest relationship-specific predictors included:
- perceived partner commitment,
- appreciation,
- sexual satisfaction,
- perceived partner satisfaction, and
- conflict.
The researchers could explain a substantial portion of people’s current relationship satisfaction from relationship-specific variables, yet predicting whose relationship would improve or deteriorate with time proved much harder (Joel et al., 2020). (pmc.ncbi.nlm.nih.gov)
Notice what is absent from the strongest predictors.
There is no scientifically measurable variable called “cosmically selected for one another.”
What matters in measurable relationships appears to include things people experience and do: commitment, appreciation, satisfaction, affection and how conflict is handled.
That is profoundly important.
It suggests that the quality of love cannot simply be reduced to finding the correct human being.
Part of love seems to be created inside the relationship itself.
But surely compatibility matters?
Absolutely.
Saying relationships are built does not mean anyone can successfully marry anyone.
People differ enormously in personality, attraction, life goals, religion, sexuality, attitudes toward children, money, family expectations, communication habits, values and lifestyle.
Compatibility matters.
A remarkable international study published in 2025 examined 10,358 participants across 43 countries and 22 languages to investigate whether people evaluated partners more positively when those partners better matched their stated ideals.
The researchers found statistically meaningful preference-matching effects. People did, to some degree, respond more positively to partners who matched what they said they wanted (Eastwick et al., 2025). (pmc.ncbi.nlm.nih.gov)
So “just choose anybody and work hard” would also be terrible advice.
The more realistic picture is:
Compatibility matters, and relationship-building matters.
You need some combination of the two.
And that brings us to mathematics.
What happens when we apply mathematics to “the one”?
Mathematics cannot tell you whom to marry.
It cannot measure love in kilograms or tell you that Abigail has a compatibility score of exactly 91.7 while Kwame is 89.2.
But mathematics is excellent at testing whether an idea is internally plausible.
Suppose the strict soulmate theory is true:
Every person has exactly one correct romantic partner somewhere among a very large population.
Consider a deliberately simplified example.
Imagine there were 100 million people in your broad potential relationship pool after accounting for age, orientation and other basic requirements.
Now suppose exactly one of those 100 million were your soulmate.
And imagine, very generously, that over your lifetime you somehow encountered 10,000 potential partners closely enough for a relationship to be possible.
If your soulmate were randomly distributed among those 100 million people, your probability of encountering that person would be:
10,000 ÷ 100,000,000 = 0.0001
or:
0.01%
That is roughly 1 chance in 10,000.
These numbers are not demographic estimates. They are a mathematical thought experiment.
But the implication is important.
If there is literally only one correct person and there is no supernatural mechanism ensuring that you meet, most people should have an extraordinarily difficult time finding that individual.
They might live in another country.
They might speak another language.
They could be born twenty years later.
They could take another bus.
Move to another city.
Attend another university.
Never download the dating application you used.
Or simply be standing in another supermarket on the afternoon when you bought milk.
The strict one-soulmate theory therefore seems to require either enormous luck or some additional idea such as providence, fate or divine guidance.
Mathematics cannot disprove the latter.
But once supernatural guidance is introduced, we have left mathematics and entered theology or metaphysics.
Here is an even more interesting mathematical problem
Suppose instead that “soulmate” means someone who exceeds an exceptionally high compatibility threshold.
Let:
N = number of possible partners
and
p = probability that any particular person is soulmate-level compatible with you.
Then the expected number of soulmate-level people is approximately:
N × p
Suppose again that your pool contained 100 million people.
Even if only one person in a million were extraordinarily compatible with you:
100,000,000 × 1/1,000,000 = 100
That would give an expected value of 100 exceptionally compatible people, not one.
Make compatibility ten times rarer:
1 person in 10 million
You would still expect about:
10 highly compatible people.
Again, this is not an empirical estimate of how many romantic partners anyone actually has. Human compatibility is far too complicated to assign a known probability like this.
The purpose of the calculation is logical.
Once soulmate status is defined through compatibility rather than supernatural assignment, nothing naturally forces the answer to equal exactly one.
There is an even stranger result
Suppose we designed the probabilities so that the average expected number of soulmates were exactly one.
In probability notation, if the expected number is λ = 1, a simple Poisson approximation gives:
Probability of zero = about 36.8%
Probability of exactly one = about 36.8%
Probability of two or more = about 26.4%
That means even a probabilistic system engineered so that people have one soulmate on average would not usually guarantee exactly one soulmate per individual.
Some people would have none.
Some would have one.
Others would have several.
To guarantee exactly one soulmate for everyone, therefore, you need something more than ordinary random compatibility.
You need a special rule:
Every person is assigned exactly one corresponding person.
That may be a legitimate spiritual belief.
But it is an assumption, not a mathematical discovery.
Mathematics has another lesson for us: good matches need not be unique
The famous work of mathematicians David Gale and Lloyd Shapley examined what is now called the stable matching problem.
Their mathematical model showed how people with different preferences could be paired so that no unmatched pair would both prefer each other to their assigned partners (Gale & Shapley, 1962). (tandfonline.com)
The important point for our discussion is that a stable matching does not always have to be unique. Under some sets of preferences, more than one stable matching can exist. Later mathematical work has specifically examined the special conditions under which stable matchings become unique. (doi.org)
Human romance is obviously far richer than a mathematical matching algorithm.
Still, the analogy is useful.
Even in a simplified mathematical universe where everybody can rank everybody else neatly, the equations do not automatically produce one mystical partner who alone can make the system work.
There may be multiple good solutions.
Human beings are considerably more complicated.
Twenty people already create hundreds of millions of possible pairings
Another way of seeing the problem is combinatorics.
If you had just 20 people and wanted to divide everyone into 10 couples, the number of possible complete pairings would be:
20! ÷ (2¹⁰ × 10!)
which equals:
654,729,075 possible pairing arrangements.
More than 654 million arrangements from only twenty people.
Of course, most would not be desirable because attraction and compatibility impose constraints.
But the calculation shows how quickly romantic possibilities multiply.
The world does not naturally look like a collection of perfectly manufactured two-piece puzzles.
It looks more like an enormous network of possible connections in which some combinations work badly, many never occur, some work reasonably well and a smaller number may become extraordinary.
Then why does one person sometimes feel completely irreplaceable?
Here we arrive at the most important distinction in the entire soulmate debate.
A person can become unique without having been the only possible person.
Imagine two people meeting at 25.
They build a home.
They survive financial problems.
They raise children.
They travel together.
They sit beside one another during illness.
They develop private jokes nobody else understands.
One comforts the other when a parent dies.
They know exactly how the other takes coffee.
They remember the terrible apartment they could barely afford at 27.
They remember being 40 together.
Then 60.
Then 80.
Mathematically, perhaps each could originally have formed a successful relationship with several other people.
But after fifty years of shared history, their relationship is no longer interchangeable.
Nobody else has those fifty years.
That person has become unique.
This suggests a different understanding of soulmate:
Maybe soulmates are not always found. Sometimes they are made.
Not manufactured artificially.
Not forced.
But created through thousands of acts of knowing, forgiving, choosing, sacrificing, laughing, touching, arguing, repairing and growing.
Could someone therefore have more than one soulmate?
There is no scientific reason to rule it out.
Consider someone happily married for thirty years whose spouse dies.
Years later, that widow or widower meets someone else and falls deeply in love.
Was the first marriage fake?
Surely not.
Does loving the second person prove the first spouse was never a soulmate?
That conclusion seems equally unnecessary.
Perhaps the person experienced two extraordinary loves under two different circumstances.
Likewise, somebody may experience one great relationship at 25 and another at 55 after divorce, bereavement or enormous personal change.
The person who suited you at 22 might not be the same type of person who suits you at 62 because you are not exactly the same person either.
Our personalities, circumstances, priorities and knowledge change.
Relationships change us too.
The soulmate question therefore contains a hidden assumption: that there is one fixed version of you requiring one fixed complementary human being.
Real life appears much more dynamic.
Your perfect match may partly depend on who you become together
There is further reason to be cautious about imagining that humans possess a permanent internal checklist capable of identifying their single ideal partner.
Research has found that people’s ideal preferences and evaluations can interact with their actual relationship experiences. And large cross-cultural research indicates that matching people’s preferences matters, but the effect is far from explaining everything about attraction and relationship quality. (sciencedirect.com)
In ordinary language:
You may have an idea of your perfect partner.
Then you meet somebody who changes your idea of perfect.
Many people discover qualities they did not know they valued until another person demonstrates them.
Someone might spend years saying:
“I need somebody exciting.”
Then eventually realise:
“What I actually treasure is someone peaceful and dependable.”
Or:
“I always wanted someone highly successful.”
until discovering:
“I care more about kindness and emotional safety.”
Love does not merely satisfy preferences.
Sometimes love educates our preferences.
What about love at first sight?
Instant attraction certainly exists.
But instant certainty and permanent compatibility are different things.
You can feel an enormous emotional or physical pull toward somebody before knowing how they respond to financial stress, whether they tell the truth when embarrassed, how they treat service workers, whether they want children, what they believe about fidelity or whether they can apologise sincerely.
Chemistry provides information.
It does not provide all information.
The mistake is not feeling:
“There is something incredibly special about this person.”
The mistake is converting that feeling into:
“Therefore I already know everything necessary to conclude that this is the only person on Earth who could ever make me happy.”
Those are completely different claims.
The “soulmate model” has even been studied in marriage
Sociologists W. Bradford Wilcox and Jeffrey Dew examined data from 1,414 married men and women in Louisiana and compared different ways people conceptualised marriage.
Their results were complex. People embracing a soulmate-oriented model could report high relationship satisfaction, yet this model was also associated in their data with higher conflict and divorce. More institutionally oriented marriages appeared more stable under certain conditions, particularly when social support and relational quality were also present (Wilcox & Dew, 2010). (sciencedirect.com)
This does not mean people should return to any particular traditional model of marriage.
The sample was specific to one U.S. state and a particular historical period.
But it reinforces a useful idea:
Feelings alone may not carry a lifetime relationship.
Long relationships also rely on commitments, habits, families, communities, shared responsibilities and repeated decisions.
Romance may begin a relationship.
Structure often helps it survive.
The soulmate paradox
Here is perhaps the biggest paradox.
People often believe:
“If this person is my soulmate, loving them should feel natural.”
But another definition may be more realistic:
“Because I love this person so deeply, I am willing to participate in building something extraordinary with them.”
One places almost all responsibility on destiny.
The other preserves romance while making room for human agency.
Perhaps healthy love needs both.
A little destiny:
“How incredible that our lives crossed.”
And a lot of growth:
“Now that they have crossed, what will we build?”
Does believing there are multiple possible partners make love less special?
This is one of the strongest objections to the multiple-soulmate idea.
If several people could theoretically have been suitable for you, doesn’t that make your spouse replaceable?
Not necessarily.
Consider friendship.
You probably could have developed a close friendship with people you never met.
Does that make your best friend meaningless?
No.
There may be thousands of cities in which you could build a happy life.
That does not mean your hometown has no significance.
You might have had several possible careers.
That does not erase the meaning of the career you chose.
Possibility does not destroy significance.
Quite the opposite.
Love can be meaningful precisely because among many possible lives, two people build one particular life together.
Your partner does not need to have been the only human being in the universe you could possibly love in order for your love to be priceless.
Perhaps “the one” is a choice, not a discovery
There is another interpretation worth considering.
Maybe “the one” is not the only possible person.
Maybe “the one” becomes the person you choose.
Under that view, you might have met several people capable of becoming wonderful long-term partners.
But eventually you choose one.
And that person chooses you.
You stop endlessly comparing real life with imaginary alternatives.
You invest.
You grow.
You build trust.
You accumulate history.
And eventually the person who was once one possibility among several becomes unlike anyone else because nobody else shares what you have created together.
There is something deeply romantic about that idea too.
Perhaps even more romantic.
It means love is not merely something happening to you.
It is something you participate in creating.
But growth does not mean staying in every relationship
This distinction is essential.
Saying that relationships require work does not mean every relationship should be saved.
Some people are genuinely incompatible.
Sometimes values differ too fundamentally.
Sometimes trust is repeatedly violated.
Sometimes one partner wants children and the other does not.
Sometimes a relationship becomes controlling, abusive or unsafe.
A growth mindset should never become:
“If I work hard enough, I must remain with this person forever.”
Relationships require two willing participants.
Effort cannot transform coercion into love.
And the existence of difficulties does not automatically mean you chose wrongly, but neither should “soulmate” language be used to excuse harmful behaviour.
So, do we have only one soulmate in a lifetime?
If by soulmate we mean:
“Exactly one predetermined human being on Earth whom you alone are supposed to marry,”
there is currently no scientific evidence establishing that claim.
Mathematics does not naturally lead us to exactly one compatible person.
Relationship psychology does not identify one uniquely destined partner.
Large studies suggest that compatibility matters, but commitment, appreciation, satisfaction, communication and relationship processes matter enormously too. (pubmed.ncbi.nlm.nih.gov)
If soulmate means:
“A person with whom I can form an exceptionally deep, loving and meaningful connection,”
then it is entirely reasonable that more than one potential person could meet that description over a lifetime.
But there is one final possibility.
Perhaps a soulmate is neither simply found nor simply assigned.
Perhaps a soulmate is someone who begins as a highly compatible person and gradually becomes irreplaceable because of what two people build together.
Science cannot tell us whether fate brought them together.
Mathematics cannot calculate the value of the memories they create.
Psychology cannot reduce fifty years of love to a spreadsheet.
And perhaps it should not try.
The deeper answer may be better than the fairy tale
The traditional soulmate story tells us:
There is exactly one person for you. Find them.
A more evidence-compatible version might say:
There may be several people with whom you could build an extraordinary relationship. Choose carefully. Then love deliberately.
That version does not remove romance.
It adds responsibility to romance.
You still get the unbelievable first meeting.
The excitement.
The attraction.
The feeling that somehow this stranger seems strangely familiar.
But after that comes something perhaps even more beautiful:
choice.
Two imperfect humans repeatedly deciding:
I am still here.
Maybe the greatest love story is not finding the only person in eight billion human beings whom you could possibly love.
Maybe it is meeting one person you could deeply love, discovering that they could deeply love you too, and then spending years transforming possibility into something unique.
So, do we have just one soulmate?
Science gives us no good reason to believe we must.
But if you spend a lifetime loving one person well, they may eventually become something mathematics cannot reproduce:
not the only person you could ever have loved, but the only person with whom you lived that particular love.
And perhaps that is enough to call someone a soulmate.
References
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Wilcox, W. B., & Dew, J. P. (2010). Is love a flimsy foundation? Soulmate versus institutional models of marriage. Social Science Research, 39(5), 687–699. doi:10.1016/j.ssresearch.2010.05.006. (sciencedirect.com)
YouGov. (2015, March 27–29). Soulmates survey toplines [Survey of 1,000 U.S. adults]. YouGov. (ygo-assets-websites-editorial-emea.yougov.net)
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Disclaimer
This article discusses romantic relationships using psychological research, public-opinion data, mathematical thought experiments and philosophical reasoning. Mathematics used in the article is illustrative and should not be interpreted as a scientific calculation of how many “soulmates” any individual actually has. The existence of souls, divine matchmaking, destiny or supernatural romantic assignment is outside what current scientific methods can establish or disprove. Relationship research describes general patterns and cannot determine whether a particular person is or is not someone’s soulmate. Readers are encouraged to consult the original sources and independently fact-check any information or interpretation they believe may require clarification or correction.
