The Science of Soulmates

Whether you're seeking a soulmate or wondering whether your partner is The One this Valentine's Day, one thing's for sure—math isn't on your side.

Sabrina Stierwalt, PhD
3-minute read
Episode #362

As Valentine’s Day approaches, couples are snuggling up and making plans for romantic gestures. That may leave those still seeking a partner wondering when they’ll meet that special someone. But how many someones are there for each of us? Do we each have just one true soulmate, that person who is the ideal fit for all of our interests, values, and personality quirks? And if you’re with someone whom you consider special, how do you know you’ve really found The One? 

The likelihood of finding your soulmate 

While it may be impossible to define a soulmate in testable, scientific terms, we can take a look at some cold, hard math to determine how likely we are to meet one particular destined-to-by-mine person on this planet full of people. In fact, Randall Munroe, former NASA engineer and author of the popular web comic xkcd, has done this for us.

First off, out of the hundred billion or so people that have walked this earth, less than 10 percent are still alive today. If we assume our soulmate could have lived during any time period, then for more than 90 percent of us, our soulmates are already dead. Bummer. And this gets worse, as you can imagine, if we have to factor in future, as-of-yet nonexistent people as potential soulmates.

If we assume our soulmate could have lived during any time period, then for more than 90 percent of us, our soulmates are already dead. Bummer.

So, Munroe instead assumes that your soulmate has to not only be alive but is likely in the same age range as you. (Big assumption; I know). This narrows the candidate list from the Earth’s population of 7.5 billion seekers-of-true-love to a mere 500 million people. 

How many strangers do you notice daily? Let’s generously suggest that this could be something like 15 people every single day. If 10 percent of those people are close enough to your age to be considered soulmate material, then in a lifetime of 80 years you might encounter and lock eyes with 50,000 soulmate candidates. That sounds like a lot! But recall that there are about 500 million people on this Earth that are in the right age range to be your soulmate. If you encounter just 50,000 of them, you've only caught the eye of 0.01 percent. As Munroe explains, that means if you lived 10,000 lifetimes, you would only find your one true soulmate once. 

So should we be looking for our soulmate?

Studies suggest that it can actually hurt your relationship to think of your partner as your soulmate. For example, those who are more likely to use words like “soulmate” or “true love” to describe their partner often report more unhappiness in their relationships. Perhaps when you're tied to the idea of there only being one person out there for you, every little disagreement can plant a seed of doubt that perhaps you have not yet found The One.

Studies suggest that it can actually hurt your relationship to think of your partner as your soulmate. 

Psychologist and researcher Dr. Shauna Springer instead suggests that we are thinking about soulmates all wrong. What if soulmates are not found but created?

We don’t expect our most brilliant musicians, our star athletes, our expert chefs, or our genius scientists to find their success through luck alone. Sure, they have to have raw talent, so there is some luck involved in that, but they also work to hone those skills. They continue to learn and practice their craft. Perhaps soulmates require the same effort and dedication as we learn and adjust to how to be better matches for each other. So, we still need some dumb luck to meet the right person, but we also have to put the work in. We have to earn that connection. 

RELATED: Are Soulmates Real

If we’re destined for only one person, the odds of finding The One are not in our favor. And what if you defy all these great odds and actually find your soulmate but the conditions aren’t right? I often tell my husband that if he had not trimmed his intensely bushy beard before we met, we probably wouldn’t be together. (Sorry, honey.) So what if you meet your soulmate but you speak different languages and can’t communicate to find out that you're destined to be together? What if you find your soulmate but they're already partnered with someone else because they erroneously think this other person is their soulmate or they just don’t believe in soulmates? Or what if you meet your soulmate but you’re having an off day, and your grumpy mood turns them off?

That’s just far too much pressure for me. But leaning into a relationship with someone you love and respect while learning to love each other’s quirks and imperfections and, dare I say, bushy beards? That I can do.


Please note that archive episodes of this podcast may include references to Ask Science. Rights of Albert Einstein are used with permission of The Hebrew University of Jerusalem. Represented exclusively by Greenlight.

About the Author

Sabrina Stierwalt, PhD

Dr Sabrina Stierwalt earned a Ph.D. in Astronomy & Astrophysics from Cornell University and is now a Professor of Physics at Occidental College.