The mathematics of love | Hannah Fry | TEDxBinghamtonUniversity

The mathematics of love | Hannah Fry | TEDxBinghamtonUniversity


Thank you very much. So, yes, I’m Hannah Fry,
I am a mathematician, and today I want to talk to you
about the mathematics of love. Now, I think that we can all agree that mathematicians
are famously excellent at finding love. But it’s not just
because of our dashing personalities, superior conversational skills
and excellent pencil cases. It’s also because we’ve actually done
an awful lot of work into the maths of how to find the perfect partner. Now, in my favorite paper
on the subject, which is entitled, “Why I Don’t Have a Girlfriend” –
(Laughter) – Peter Backus tries to rate
his chances of finding love. Now, Peter’s not a very greedy man. Of all of the available women in the U.K., all Peter’s looking for
is somebody who lives near him, somebody in the right age range, somebody with a university degree, somebody he’s likely to get on well with, somebody who’s likely to be attractive, somebody who’s likely
to find him attractive. (Laughter) And comes up with an estimate
of 26 women in the whole of the UK. It’s not looking very good, is it Peter? Now, just to put that into perspective, that’s about 400 times fewer
than the best estimates of how many intelligent
extraterrestrial life forms there are. And it also gives Peter
a 1 in 285,000 chance of bumping into any one
of these special ladies on a given night out. I’d like to think
that’s why mathematicians don’t really bother
going on nights out anymore. The thing is that I personally don’t subscribe
to such a pessimistic view. Because I know,
just as well as all of you do, that love doesn’t really work like that. Human emotion isn’t neatly ordered
and rational and easily predictable. But I also know that that doesn’t mean that mathematics hasn’t got something
that it can offer us because, love, as with most of life,
is full of patterns and mathematics is, ultimately,
all about the study of patterns. Patterns from predicting the weather
to the fluctuations in the stock market, to the movement of the planets
or the growth of cities. And if we’re being honest,
none of those things are exactly neatly ordered
and easily predictable, either. Because I believe that mathematics
is so powerful that it has the potential to offer us a new way of looking
at almost anything. Even something as mysterious as love. And so, to try to persuade you of how totally amazing, excellent
and relevant mathematics is, I want to give you my top three
mathematically verifiable tips for love. Okay, so Top Tip #1: How to win at online dating. So my favorite online dating website
is OkCupid, not least because it was started
by a group of mathematicians. Now, because they’re mathematicians, they have been collecting data on everybody who uses their site
for almost a decade. And they’ve been trying
to search for patterns in the way that we talk about ourselves and the way that we interact
with each other on an online dating website. And they’ve come up with some
seriously interesting findings. But my particular favorite is that it turns out
that on an online dating website, how attractive you are
does not dictate how popular you are, and actually, having people think
that you’re ugly can work to your advantage. Let me show you how this works. In a thankfully voluntary
section of OkCupid, you are allowed to rate
how attractive you think people are on a scale between 1 and 5. Now, if we compare this score,
the average score, to how many messages
a selection of people receive, you can begin to get a sense of how attractiveness links to popularity
on an online dating website. This is the graph that the OkCupid guy
shave come up with. And the important thing to notice
is that it’s not totally true that the more attractive you are,
the more messages you get. OK, there’s maybe a bit of a trend there, but it’s got an R squared
of absolutely naff all, let’s be honest. But the question arises then
of what is it about people up here who are so much more popular
than people down here, even though they have the same
score of attractiveness? And the reason why is that it’s not just
straight forward looks that are important. So let me try to illustrate
their findings with an example. So if you take someone like
Portia de Rossi, for example, everybody agrees that Portia de Rossi
is a very beautiful woman. Nobody thinks that she’s ugly,
but she’s not a supermodel, either. If you compare Portia de Rossi
to someone like Sarah Jessica Parker, now, a lot of people,
myself included, I should say, think that Sarah Jessica Parker
is seriously fabulous and possibly one
of the most beautiful creatures to have ever have walked
on the face of the Earth. But some other people,
i.e., most of the Internet, seem to think that she looks
a bit like a horse. (Laughter) Now, I think that if you ask people
how attractive they thought Sarah Jessica Parker
or Portia de Rossi were, and you ask them to give them
a score between 1 and 5, I reckon that they’d average out
to have roughly the same score. But the way that people would vote
would be very different. So Portia’s scores would
all be clustered around the 4 because everybody agrees
that she’s very beautiful, whereas Sarah Jessica Parker
completely divides opinion. There’d be a huge spread in her scores. And actually it’s this spread that counts. It’s this spread
that makes you more popular on an online Internet dating website. So what that means then is that if some people
think that you’re attractive, you’re actually better off having some other people think
that you’re a massive minger. That’s much better
than everybody just thinking that you’re the cute girl next door. Now, I think this begins
makes a bit more sense when you think in terms of the people
who are sending these messages. So let’s say that you think
somebody’s attractive, but you suspect that other people
won’t necessarily be that interested. That means there’s
less competition for you and it’s an extra incentive
for you to get in touch. Whereas compare that to
if you think somebody is attractive but you suspect that everybody
is going to think they’re attractive. Well, why would you bother
humiliating yourself, let’s be honest? Here’s where the really
interesting part comes. Because when people choose the pictures
that they use on an online dating website, they often try to minimize the things that they think some people
will find unattractive. The classic example is people who are,
perhaps, a little bit overweight deliberately choosing
a very cropped photo, or bald men, for example, deliberately choosing pictures
where they’re wearing hats. But actually this is the opposite
of what you should do if you want to be successful. You should really, instead, play up to
whatever it is that makes you different, even if you think that some people
will find it unattractive. Because the people who fancy you
are just going to fancy you anyway, and the unimportant losers who don’t,
well, they only play up to your advantage. Okay, Top Tip #2:
How to pick the perfect partner. So let’s imagine then
that you’re a roaring success on the dating scene. But the question arises of how do you then
convert that success into longer-term happiness
and in particular, how do you decide
when is the right time to settle down? Now generally,
it’s not advisable to just cash in and marry the first person
who comes along and shows you any interest at all. But, equally, you don’t really
want to leave it too long if you want to maximize your chance
of long-term happiness. As my favorite author,
Jane Austen, puts it, “An unmarried woman of seven and twenty can never hope to feel or inspire
affection again.” (Laughter) Thanks a lot, Jane.
What do you know about love? So the question is then, how do you know when
is the right time to settle down given all the people
that you can date in your lifetime? Thankfully, there’s a rather delicious bit
of mathematics that we can use to help us out here, called
optimal stopping theory. So let’s imagine then, that you start dating when you’re 15 and ideally, you’d like to be married
by the time that you’re 35. And there’s a number of people that you could potentially
date across your lifetime, and they’ll be at varying levels
of goodness. Now the rules are that once you cash in
and get married, you can’t look ahead to see
what you could have had, and equally, you can’t go back
and change your mind. In my experience at least, I find that typically people don’t
much like being recalled years after being passed up
for somebody else, or that’s just me. So the math says then
that what you should do in the first 37 percent
of your dating window, you should just reject everybody
as serious marriage potential. (Laughter) And then, you should pick
the next person that comes along that is better than everybody
that you’ve seen before. So here’s the example. Now if you do this, it can be
mathematically proven, in fact, that this is the best possible way of maximizing your chances
of finding the perfect partner. Now unfortunately, I have to tell you that
this method does come with some risks. For instance,
imagine if your perfect partner appeared during your first 37 percent. Now, unfortunately,
you’d have to reject them. (Laughter) Now, if you’re following the maths, I’m afraid no one else comes along that’s better than anyone
you’ve seen before, so you have to go on
rejecting everyone and die alone. (Laughter) Probably surrounded by cats
nibbling at your remains. Okay, another risk is,
let’s imagine, instead, that the first people that you dated
in your first 37 percent are just incredibly dull,
boring, terrible people. Now, that’s okay,
because you’re in your rejection phase – that’s okay,
because you’re in your rejection phase, so thats fine, you can reject them. But then imagine, the next person
to come along is just marginally less boring,
dull and terrible than everybody that you’ve seen before. Now, if you are following the maths,
I’m afraid you have to marry them and end up in a relationship
which is, frankly, suboptimal. Sorry about that. But I do think that there’s
an opportunity here for Hallmark to cash in on
and really cater for this market. A Valentine’s Day card like this.
(Laughter) “My darling husband,
you are marginally less terrible than the first 37 percent
of people I dated.” It’s actually more romantic
than I normally manage. Okay, so this method doesn’t give you
a 100 percent success rate, but there’s no other possible
strategy that can do any better. And actually, in the wild,
there are certain types of fish which follow
and employ this exact strategy. So they reject every possible suitor
that turns up in the first 37 percent
of the mating season, and then they pick the next fish
that comes along after that window that’s, I don’t know, bigger and burlier than all of the fish
that they’ve seen before. I also think that subconsciously,
humans, we do sort of do this anyway. We give ourselves a little bit of time
to play the field, get a feel for the marketplace
or whatever when we’re young. And then we only start looking seriously
at potential marriage candidates once we hit our mid-to-late 20s. I think this is conclusive proof,
if ever it were needed, that everybody’s brains are prewired
to be just a little bit mathematical. Okay, so that was Top Tip #2. Now, Top Tip #3: How to avoid divorce. Okay, so let’s imagine then
that you picked your perfect partner and you’re settling into
a lifelong relationship with them. Now, I like to think that everybody
would ideally like to avoid divorce, apart from, I don’t know,
Piers Morgan’s wife, maybe? But it’s a sad fact of modern life that 1 in 2 marriages
in the States ends in divorce, with the rest of the world
not being far behind. Now, you can be forgiven, perhaps for thinking that the arguments
that precede a marital breakup are not an ideal candidate
for mathematical investigation. For one thing, it’s very hard to know what you should be measuring
or what you should be quantifying. But this didn’t stop a psychologist,
John Gottman, who did exactly that. Gottman observed hundreds of couples
having a conversation and recorded, well,
everything you can think of. So he recorded what was said
in the conversation, he recorded their skin conductivity, he recorded their facial expressions, their heart rates, their blood pressure, basically everything apart from whether
or not the wife was actually always right, which incidentally she totally is. But what Gottman and his team found was that one of the most important
predictors for whether or not a couple
is going to get divorced was how positive or negative each partner
was being in the conversation. Now, couples that were very low-risk scored a lot more positive points
on Gottman’s scale than negative. Whereas bad relationships, by which I mean, probably
going to get divorced, they found themselves
getting into a spiral of negativity. Now just by using these very simple ideas, Gottman and his group were able to predict whether a given couple
was going to get divorced with a 90 percent accuracy. But it wasn’t until he teamed up
with a mathematician, James Murray, that they really started to understand what causes these negativity spirals
and how they occur. And the results that they found I think are just incredibly
impressively simple and interesting. So here they are. I think that should be fairly clear. So these equations, they predict how
the wife or husband is going to respond in their next turn of the conversation, how positive or negative
they’re going to be. And these equations, they depend on the mood of the person
when they’re on their own, the mood of the person when
they’re with their partner, but most importantly, they depend on how much the husband and wife
influence one another. Now, I think it’s important
to point out at this stage, that these exact equations
have also been shown to be perfectly able at describing what happens between two countries
in an arms race. (Laughter) So that – an arguing couple
spiraling into negativity and teetering on the brink of divorce – is actually mathematically equivalent
to the beginning of a nuclear war. (Laughter) But the really important term
in this equation is the influence that people
have on one another, and in particular, something called
the negativity threshold. Now, the negativity threshold, you can think of as
how annoying the husband can be before the wife starts to get
really pissed off, and vice versa. Now, I always thought that good marriages
were about compromise and understanding and allowing the person
to have the space to be themselves. So I would have thought that perhaps
the most successful relationships were ones where there was
a really high negativity threshold. Where couples let things go and only brought things up
if they really were a big deal. But actually, the mathematics
and subsequent findings by the team have shown the exact opposite is true. The best couples,
or the most successful couples, are the ones with
a really low negativity threshold. These are the couples that don’t let
anything go unnoticed and allow each other
some room to complain. These are the couples that are continually
trying to repair their own relationship, that have a much more positive
outlook on their marriage. Couples that don’t let things go and couples that don’t let trivial things
end up being a really big deal. Now of course, it takes bit more
than just a low negativity threshold and not compromising to have
a successful relationship. But I think that it’s quite interesting to know that there is really
mathematical evidence to say that you should never
let the sun go down on your anger. So those are my top three tips of how maths can help you
with love and relationships. But I hope
that aside from their use as tips, they also give you a little bit of insight
into the power of mathematics. Because for me, equations and symbols
aren’t just a thing. They’re a voice that speaks out
about the incredible richness of nature and the startling simplicity in the patterns that twist and turn
and warp and evolve all around us, from how the world works to how we behave. So I hope that perhaps,
for just a couple of you, a little bit of insight into
the mathematics of love can persuade you to have a little bit
more love for mathematics. Thank you. (Applause)

100 thoughts on “The mathematics of love | Hannah Fry | TEDxBinghamtonUniversity

  1. Yes, the odds are absurd now. If I simply put everyone of the gender I am interested in within the Metro area. I only included the age range of 18-44 due to the fact that these are wide census ranges that include the smaller range that I would be interested in.
    The number I estimated 4% of the population would be interested in me, not including age range. Roughly 14074 people within the hour and a half driving range. The fact that you likely cannot keep a relationship going outside of a 30 minute drive would reduce the number to a non-precise 4223 options . This doesn't consider anything to do with personality limitations or attractiveness or anything else. However, if you believe the Meyer-Briggs concepts as applied to dating. The number drops to 15 people. Apparently I am a rare type who only likes other particular small groups. Throw in the fact that I only meet people online in a very narrow range, and that number likely drops to 1 or 2 options.

    Interestingly, OkCupid has told me I have 1985 likes over an 8 year period of being online. I have had roughly 15 or so dates over that time, and only two relationships. The numbers are not good. A lot of those likes are from thousands of miles away as well.

    My research shows me that I will never again have a relationship from OkCupid unless I change a lot of factors of my life.

  2. Shouldn’t the card read “You’re marginally less terrible than the men I dated during the first 37% of my predicted optimal dating years” instead of the first 37% of men?

  3. My takeaway from this: There’s hope for massive minger gingers like me!I’m going to binge listen the Curious Cases podcast. Dr Fry gives me hope 😁

  4. Very sad! The same talk about monogamic, heteronormative, and violent relationships. For how long we'll reinforce this meaning of "Love"?

  5. Ok I believe you hannah I fell for you thanks for being you your beautiful and seem to be really nice and funny wow you got everything but your missing something me

  6. I would have an entirely disparate relationship with mathematics if I'd have such a teacher.
    Also the jon gottman study is described elaborately in Malcolm gladwell's Blink.

  7. Tips
    1. For online dating, emphasize your unique (and perhaps unflattering/divisive) parts of yourself.
    2. Reject the first 37% of dates and settle for the next one that's better than them all.
    3. Have a really low negativity threshold – sound out any negativities with your partner ASAP

  8. Can you help me with a consideration of a mathematically geometrical problem? Please? How many equilateral triangles can you fit into a right triangle a la Pythagoras, if you encode the golden ratio, psi or more insightfully creative ratios?

  9. I mean… I think this shows just how hard and complicated it is to get and stay married. Why wouldn't someone simply put that effort into themselves and, I don't know, not get married? Seems like there's little to no payoff… Don't want to die alone? That's a weird argument since we all die alone… I mean, statistically if a guy gets married and stays married, he's gonna die before her, so she'll end up dying alone anyway. There's a ton of other options out there besides marriage, all of which appear to have a much higher chance of success with higher levels of fulfillment and satisfaction from a statistical standpoint. So weird people are who keep trying to justify marriage… It's like they are self destructive or something… but maybe that's just me.

  10. Jesus Christ. Come up with some more interesting comments. 60%+ Of you basically just saying you want to bang her. So do I, but we ALL get it. Absolutely no popcorn for your discussion, too boring.

  11. all the assumptions on this video are wrong:
    – meeting an marrying a person you meet on a dating website to get started with

    to put it straight:
    – things happen when they have to happen
    – things happen when you are prepared to have the opportunity
    – things happen when you are prepared to turn that opportunity into a relationship
    – things happen if you have resilience and can keep a relationship in the long run

    to put it straight:
    – all relationships have some manifested hardship at some point
    – it's willing to you to surprass that and deal with that

  12. I got lucky wife has been chasing me sense 12 years old and we've been on our honeymoon for 24 years and counting. Now with that said this info may have been helpful when I was younger haha great presentation.

  13. This crowd is absolutely boring. Her talk was amazing and funny. And by the way for science lovers there's a podcast that she does. It goes by the name 'The curious case of rutherford and Fry' from the BBC.

  14. Wow! She threw a shizzt ton of shade. On Jessica Parker, Piers Morgan. Lol. This woman is awesome. I am in love! I wish I was 37.000001% man.

  15. One day, she will complete the equation and solves the gravity problem that prevent interstellar travel, ultimately saving humanity.

  16. i'm not a native speaker. There's the comment about Jane Austen that I don't understand. What does she mean by a woman of seven and twenty?

  17. Attempting to use statistics to measure something as complex as human mate selection / pair bonding seems to me akin to using a yardstick when you need to measure in millimeters. You might get some ideas about broad patterns and trends. But, so much of that process relies on the unconscious that you are missing the really interesting parts that merit investigation.

  18. What metrics were used to quantify both the wife and husband’s assigned mood values? Seems like those metrics in such a study could be quite arbitrary.

  19. Is it weird that I want to maths her brains out? I'd happily marry her before or after this, but there's no question about it; I'd maths the snot out of her, numerate all over it, then maths it back in!

  20. How to win a online dating if your name is Hannah Fry:
    Show them a picture of you, and let them know that you are just as smart as you are beautiful.. 😉

  21. According to the Equations of "coulples' responses" there seems to be strong correlation between those two, but what if the situation is such, that the correlation is oposite? How probability is working in those situations?

  22. I wonder if where compatible …..i would really have to ask you out for a cup of tea

  23. Spiral of negativity, leads to nuclear war and divorce.
    I am sending a link all my ex's. Spread the knowledge!

  24. Hannah, I have to admit that I have fallen in love with you for the duration of the video, but unfortunately it appears to me now as I go through the comments that so has everyone else, therefore I think I'm just not going to do anything about it. I mean, why even bother, taking into account all the competition? You must have trillions of people hitting on you every day.

  25. Hahahahaha, the tables are turning, aren't they? Now the women need help attracting men, because the smart and successful men have gone MGTOW.

  26. I was shocked with the 37% theory. I was ready to seriously date for marriage from 25 until im 33(this is my cut off). Hence my 37% should be at age 28. Without knowing this, i marry my husband at 28. Same with my hubby. We got same same 37% optimal.

  27. My Life has become so much easier & prosperous once I completely gave up on the idea of marriage and relationships. Women = CHEAP THRILL THAT'S WAY OVERPRICED

  28. I’m confused… how do you “reject the first thirty seven percent” of an amount of people of which you don’t know the maximum of. I mean, how do you know when you’ve reached the 37% if you don’t know the total amount?

  29. About the thing with nuclear war, I think that when you and your partner actually fall in love you both already have zero sum capacity because if things go sideways both will be terribly hurt, even if you end up as friends, so every time you choose to express affection and positivity towards your loved one you are in fact your own Stanislav Petrov

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