with the opposite sex. But it's not just because of our dashing personalities and superior

pencil cases. Oh no. It's also because we've have done an awful lot of work in the mathematics

of, how to find the perfect partner. In my favourite paper on the subject, entitled

"Why I don't have a girlfriend", Peter Backus tries to work out his chances of finding love.

In particular, he is looking for single women who live near him in the UK, are of the right

age range, have an university degree, are likely to be attractive, and he is likely

to get in well with. And the total he comes up with is 26 in the whole of the UK.

Now to just put that in perspective that's 400 times fewer than the best estimates of

how many intelligent extra-terrestrial life forms there are. And it gives him a 1 in 285,000

chance of meeting one of these 26 ladies on a given night out. It's not looking very good

is it Peter? Now I don't prescribe to this frankly pessimistic

view. I think there is a lot of people you can have a successful relationship with if

you want to. But given all the people you'll date throughout your life time, how do you

know when is the right time to settle down? Of course it isn't wise to cash in the first

person who shows you any interest, but equally if you want to be truly happy you can't leave

it too long. As my good friend Jane Austin says "An unmarried woman of seven and twenty

can never hope to feel or inspire affection again." Yeah, thanks a lot Jane, what do you

know about love? But the thing about dating is that once you've

made up your mind, you can't go back and change it. Typically people aren't that happy being

recalled later after being passed up for somebody else. So many people should you date before

you decide to settle down? Now, if only there were some kind of a mathematical

formula for a dating strategy that we could use to help us. Oh wait, there totally is!

And its called optimal stopping theory. So, let's say you start dating at about 15

years old and ideally you'd like to settle down at 35. And the rules are you can't see

ahead of what you could've had once you settle down and you can't go back and change your

mind. So the theory says that in the first 37% (or 1 over e) of your dating time, you

should reject everybody as serious marriage material. And after that period has passed

you should pick the next person that comes along that is better than everybody else you've

seen before. And if you do that it can be mathematically proven that you're maximising

your chances of picking the perfect partner. So this method has been observed in the wild.

So certain types of fish will reject any suitor who comes along within the first 37% of the

mating season and then pick the next male fish that comes along that's bigger and burlier

than all of the rest. But you could also use this strategy when

you're looking to buy or rent a house. Say you got three months in which to look for

a house. You should spend the first month (30% of the time window) just getting a feel

for the market, going to see houses but never cashing in on any of them. And after that

period has passed you then pick the first house that comes along that is better than

everything else you've seen before. Now this method does come with risks, it doesn't

guarantee that you'll get the perfect partner, it just gives you your best chance of finding

them. You could, for instance, be really unlucky and have your perfect match appear within

that first 37% window when you're rejecting everybody. And if that's the case, unfortunately

the maths says that you'll grow old alone probably be surrounded by cats.

Or let's say you got really unlucky and the first 37% of the people you dated were just

incredibly dull and boring and terrible people. And that's ok because you're still rejecting

all of those people. But let's say the next person that comes along is still really dull

and boring but marginally less terrible everybody you'd seen before. If you're following the

maths and marry that person you'd just be in a relationship that was suboptimal. Sorry

about that. But if everybody followed this strategy then

one in three people who do, they can settle down in the knowledge that maths says they'd

done the very best they can.