The mathematics of love

Today i want to talk to you

about the mathematics of love.

I think we can all agree
that mathematicians

are famously excellent
at finding love.

But it's not just because
of our dashing personalities

our superior conversational skills

or our excellent pencil cases,

it's also because we've done

a lot of work into the maths

of how to find the perfect partner.

in my favorite paper on the subject

which is entitled,

"Why I Don't Have a Girlfriend."

peter backus tries to rate

his chances at finding love

now, peter is not a very greedy man

of all of the available women in the UK

all that 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 attractive

somebody who is 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
extra-terrestrial life forms there are

and it also gives peter a

1 in 285,000 of bumping
into any one of these special ladies

on a night out

I'd like to think that's why

mathematicians don't really bother

going on nights out anymore

The thing is is that i personally

don't subscribe to such a pessimistic view

i know, just as well as you do,

that love doesn't really work like that

human emotion isn't neatly ordered

rational or easily predictable

but i also know that that doesn't mean
that mathematics

doesn't have something 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

pattersn from predicting the weather

to the fluctuations of the stock market

to the movement of the planets

or the growth of cities

if we're being honest, none

of those things are neatly ordered

or easily predictable either

because i believe that mathematics

is so powerful that is 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, 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 OkayCupid

not least because it was

started by a group of mathematicians

now because they're mathematicians

they have been collecting

data on everyone whose been using

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 online dating websites

and they've come up with

seriously interesting findings

but my particular favorite

is that it turns out

that one 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

okay, in a thankfully voluntary section

you are allowed to rate how attractive people are

between 1 and 5

and if we compare this score

this 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 online dating

so this is a graph that the online

okay cupid guys have 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

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

if you take someone like porcia di rossi

everybody agrees that porcia di rossi

is a very beautiful woman

nobody thinks that she's ugly

but she's not a supermodel

if you compare porcia di rossi

to someone like sarah jessica parker

now, a lot of people

myself included

think that sarah jessica parker

is seriously fabulous

and possibly one of

the most beautiful creatures to have evr

walked the face of the earth

but, some other people

e.i., 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 sarah jessica parker
or porcia di rossi are

and you ask them to give them a score between one and five

i reckon that they would average out to the same score

but the way that people would vote

would be dry different

so porcia's scores would all be clustered around

the four because everybody agrees that she's

very beautiful

whereas sarah jessica parker divides opinion

there a huge spread in her scores

and actually it's this spread that counts

it's this spread that makes you more popular

on online internet dating websites

so what this 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
thinking that you're the cute girl next door

i think that this 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