Just no rhythm in algorithmic love
Despite promises, computers can’t do matchmaking, writes Tim Harford
IHAVE wondered whether the secret to love is mathematics, and I’m not the only one. Maths is full of perky ideas about matching or sorting that have a veneer of romantic promise. But for all their beauty and cleverness, one often feels that such ideas are a better introduction to mathematics than to dating and mating.
Consider the Gale-Shapley algorithm, which dates from 1962 but won Lloyd Shapley a Nobel memorial prize in economics just a couple of years ago. It is a way of assigning matching pairs in a stable way, meaning that no two people would do better ignoring the algorithm and instead making a side arrangement. The GaleShapley algorithm can be used for matching students to university places, or kidney donors to recipients. But it is most famously described as a way of allocating romantic partners. It is, alas, illsuited to this task, since it skips the possibility of homosexuality, bisexuality, polyamory or even something as simple as divorce.
But if pure mathematics cannot help, surely statistics can? Internet dating promises to move us from abstractions to the gritty reality of data. Simply type in everything you have to offer in great detail and let the computer algorithm find your match.
Such promises have been made before. Journalist Matt Novak unearthed an article from 1924’s Science and Invention magazine in which the publisher Hugo Gernsback explained that humans would soon enjoy the same scientific matchmaking approach lavished on horses. The science included the “electrical sphygmograph” (it takes your pulse) and a “body odour test”.
Then in the 1960s enterprising Harvard students set up “Operation Match”, a matchmaking service powered by a punch-card IBM computer. This was no more scientific than Mr Gernsback’s sphygmograph. According to Dan Slater’s Love in the Time of Algorithms, the men who founded Operation Match were hoping for the first pick of the women themselves. One subscriber expressed the advantages and limitations of digital dating well: “I approve of it as a way to meet people, although I have no faith in the questionnaire’s ability to match compatible people.”
Quite so. Operation Match was an easy way to reach lots of nearby singles. There should be no pretence the computer could actually pair up couples ideally suited.
Perhaps we simply need more data? OkCupid, a dating site with geek appeal and a witty, naughty tone, allows you to answer thousands of questions: anything from “Do you like the taste of beer?” to “Would you ever read your partner’s e-mail?” Users typically answer several hundred such questions, and indicate what answer they would hope for from a would-be date, and how impor- tant they feel the question is.
Again, media reaction has been credulous. Every now and then we hear of nerds who are living the dream, playing OkCupid’s algorithms with such virtuosity that love is theirs to command. Wired magazine introduced us to Chris McKinlay, “the math genius who hacked OkCupid”. Mr McKinlay, we are told, downloaded a data set containing 20,000 women’s profiles and 6million questionnaire answers, optimised his own profile and unleashed an army of software bots to draw women in. He was a data-driven love-magnet.
But OkCupid’s own research suggests this is all rather futile. In one controversial experiment, it took a collection of pairs of users who were a poor match, according to the OkCupid algorithm, and then told them that they were highly compatible. One might expect that these not-really-compatible couples would find their conversations quickly fizzled. In fact, they did scarcely less well than couples where the algorithm genuinely predicted a match. In short, whether the computer reckons you’re a love match or not isn’t a piece of information anyone should take seriously.
Hannah Fry, author of The Mathematics of Love, expresses the problem neatly. The algorithm, she says, “is doing exactly what it was designed to do: deliver singles who meet your specifications. The problem here is that you don’t really know what you want.” Quite so. The list of qualities we might want in a partner — “fascinating, sexy, fun, handsome, hilarious” — are a poor match for the list of qualities one could share with a computer database, such as “likes beer, board games, Malcolm Gladwell and redheads”. If the computer cannot pose the right questions it is hardly likely to produce the right answers.
As for Chris McKinlay, we all wish him well. He announced his engagement to Christine Tien Wang, the 88th woman he met after months in a perfect dating storm. His experience suggests that just as with Operation Match, the matching process is nonsense and the secret to finding love is to date a lot of people. © The Financial Times Limited 2015
If it cannot pose the right questions, it is hardly likely to produce the right answers