Hannah Fry - The Mathematics of Love: Patterns, Proofs, and the Search for the Ultimate Equation

First published in Great Britain by Simon & Schuster UK Ltd, 2015
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Copyright 2015 by Dr Hannah Fry

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Id like to begin with a confession: I am not an expert in love. I have never taken a course in psychology; I understand only the basics of human biochemistry; and my own dating history much like everyone elses is a mixed bag of successes mingled with a healthy series of disasters.

What I am, however, is a mathematician. And in my day job of teasing out and understanding the patterns in human behaviour, Ive come to realize that mathematics can offer a new way of looking at almost anything even something as mysterious as love.

My aim in writing this book is not to replace any of the other excellent sources available on the science of human connection. I wouldnt be qualified to describe the intangible thrill, all-consuming passion or world-ending despair that love can bring. If thats what youre after, might I recommend you simply turn to nearly every painting, poem, sculpture or song created over the last five thousand years.

Instead, I want to try and offer you a different perspective on the most talked-about subject in the history of human existence, using mathematics as a guide.

You would be forgiven for thinking that love and mathematics dont seem to naturally sit well together. Human emotions, unlike mathematical equations, are not neatly ordered or well behaved, and the real thrill and essence of romance cant easily be defined.

But that doesnt mean that mathematics doesnt have something to offer. Because mathematics is ultimately the study of patterns predicting phenomena from the weather to the growth of cities, revealing everything from the laws of the universe to the behaviour of subatomic particles. And if we consider them honestly, none of those things are neatly ordered or easily predictable either.

Thankfully, love as with most of life is full of patterns: from the number of sexual partners we have in our lifetime to how we choose who to message on an internet dating website. These patterns twist and turn and warp and evolve just as love does, and are all patterns which mathematics is uniquely placed to describe.

The maths will offer a number of dating insights, but I have another confession: the aim of this book isnt just to illuminate your love life. My hope is also to illuminate how beautiful and relevant maths is. I wanted to write this book because Im always a bit disappointed with the way that maths is viewed so negatively by the general public, even if Im not surprised that it has such a bad reputation. Most peoples only experience of mathematics is as their most hated subject at school: the topics seemed uninspiring, the ideas hadnt changed in hundreds of years and the answers were all written in the back of the textbook. Its no wonder some people think maths has nothing new to offer. But this just couldnt be further from the truth.

Mathematics is the language of nature. It is the foundation stone upon which every major scientific and technological achievement of the modern era has been built. It is alive, and it is thriving. As the physicist and writer Paul Davies puts it:

No one who is closed off from mathematics can ever grasp the full significance of the natural order that is woven so deeply into the fabric of physical reality.

To try to convince you of how insightful, relevant and powerful mathematics can be, Ive deliberately tried to choose the one subject that seems as far away from equations and proofs as possible and show how even in that context maths still has something to offer. I want to share with you my favourite mathematically verifiable ways of understanding how love can work.

Well calculate your chances of finding the person youve been waiting for. Ill show you a mathematical argument to justify approaching someone in a bar. And well even perform some mathematical tricks to help you to smoothly plan your wedding.

Ive framed most of the examples using the traditional story of man meets woman. This is simply because having two clear groups targeting each other can help to make the maths a lot simpler. The choice of examples aside, though, all of the results and tips in the book are general enough to apply to any gender and sexuality.

On occasion well use data from real-life couples to offer a strategy for singles in search of someone special. At other times well stray into abstraction and oversimplification (as mathematicians so often have a habit of doing) in the hunt for insight. There are elements of economics and science in many of the examples, but the mathematics is always there, even when its sometimes playing a more subtle role. The examples might not always apply directly to your own love life, but I hope that you will find them interesting regardless.

Most of all, though the goal of this book is to reveal the patterns that govern one of lifes greatest mysteries, my great hope is that a little bit of insight into the mathematics of love might just inspire you to have a little bit more love for mathematics.

In many ways, were all the same. Personal quirks aside, few of us would turn down the chance to experience true, romantic love. In one form or another, we are all united by a private quest for lasting happiness. Learning how to attract and keep the partner of your dreams are important aspects of this mission that well come to later, but they wont mean anything until youve found that special someone to target with your affections.

For those of us who have been single for any length of time, finding someone special can sometimes feel like an insurmountable challenge. A few years of dating a succession of boring Bernards and psycho Suzys can leave us frustrated and disappointed and feeling like the odds are stacked against us. And some people will tell you that your feelings arent necessarily unfounded. In fact, in 2010 mathematician and long-standing singleton Peter Backus even calculated that there were more intelligent alien civilizations in the galaxy than potential girlfriends for him to date.