The fascinating, if sometimes disturbing, data from online dating sites tells us that single people predictably are drawn to certain qualities. But should they be drawn to these qualities?

If you are like the average single dater – predictably clicking on people with the traits the scientists found are most desired – are you going about dating correctly? Or are you dating all wrong?

Recall, earlier I discussed the research of Samantha Joel and co-authors. Recall that they found that it was surprisingly difficult to predict whether a person was happy with a romantic partner based on a large list of traits.

There is not a set of traits that guarantee romantic happiness or preclude romantic happiness. And no algorithm in the world can predict, with enormous accuracy, whether two people will end up happy together.

That said, there was some predictive power in some traits, some factors that do increase the odds at least somewhat that a person will be happy in their romantic relationship. I will now discuss what does predict romantic happiness – and how little it has to do with the qualities that people look for in a romantic partner.

Say there is a person, John, and he is partnered with Sally. You want to predict whether John is happy in the relationship. You are allowed to ask John and/or Sally any three questions about themselves and use this information to predict John’s relationship happiness.

What questions would you want to ask? What would you want to know about the two members of this couple?

According to my read of the research of Joel and her co-authors, as well as some other research in relationship science, the best three questions to figure out whether John is happy with Sally would have nothing to do with Sally; in fact, all would be related to John. The best questions to predict John’s happiness with Sally might look something like this:

“John, were you satisfied with your life before you met Sally?”

“John, were you free from depression before you met Sally?”

“John, did you have a positive affect before you met Sally?”

Researchers have found that people who answered “yes” to questions such as these are significantly more likely to report being happy in their romantic relationship. In other words, a person who is happy outside their relationship is far more likely to be happy inside their relationship, as well.

Further – and this was quite striking – how a person answered questions about themselves was roughly four times more predictive of their relationship happiness than all the traits of their romantic partner combined.

Of course, the finding that one’s happiness outside of a relationship can have an enormous impact on one’s happiness inside that relationship is hardly a revolutionary idea. Consider this saying that was featured on Daily Inspirational Quotes: “Nobody can make you happy until you’re happy with yourself first.”

This is the type of quote that often makes cynical data geeks like myself roll our eyes. However, now, after reading the work of Joel and her co-authors, I have become convinced that this quote is largely true.

This relates to an important point about living a data-driven life. We data geeks may be most excited when we learn of a finding that goes against conventional wisdom or clichéd advice. This plays to our natural need to know something that the rest of the world doesn’t. But we data geeks must also accept when the data confirms conventional wisdom or clichéd advice. We must be willing to go wherever the data takes us, even if that is to findings like those featured on Daily Inspirational Quotes.

So, as discovered by both a team of 86 scientists and whoever writes Daily Inspirational Quotes, one’s own happiness outside a relationship is by far the biggest predictor of one’s happiness in a romantic relationship.

But what else predicts romantic happiness beyond one’s own pre-existing mental state? What qualities of a mate are predictive of romantic happiness? Let’s start with the qualities of one’s mate that are least predictive of romantic happiness.

Among more than 11,000 long-term couples, machine learning models found that the traits listed below, in a mate, were among the least predictive of happiness with that mate. Let’s call these traits the Irrelevant Eight, as partners appear about as likely to end up happy in their relationship when they pair off with people with any combo of these traits:

What should we make of this list, the Irrelevant Eight? I was immediately struck by an overlap between the list of irrelevant traits and another data-driven list discussed in this chapter.

Recall that I had previously discussed the qualities that make people most desirable as romantic partners, according to Big Data from online dating sites. It turns out that that list – the qualities that are most valued in the dating market, according to Big Data from online dating sitesal – most perfectly overlaps with the list of traits in a partner that don’t correlate with long-term relationship happiness, according to the large dataset Joel and her co-authors analysed.

Consider, say, conventional attractiveness. Beauty, you will recall, is the single most valued trait in the dating market; Hitsch, Hortaçsu, and Ariely found in their study of tens of thousands of single people on an online dating site that who receives messages and who has their messages responded to can, to a large degree, be explained by how conventionally attractive they are.

But Joel and her co-authors found, in their study of more than 11,000 long-term couples, that the conventional attractiveness of one’s partner does not predict romantic happiness. Similarly, tall men, men with sexy occupations, and people of certain races are valued tremendously in the dating market. But ask thousands of long-term couples and there is no evidence that people who succeeded in pairing off with mates with these desired traits are any happier in their relationship.

If I had to sum up, in one sentence, the most important finding in the field of relationship science, thanks to these Big Data studies, it would be something like this (call it the First Law of Love): In the dating market, people compete ferociously for mates with qualities that do not increase one’s chances of romantic happiness.

Moreover, if I had to define the qualities that are highly desired even though they don’t lead to long-term romantic happiness, I would call many of them shiny qualities. Such qualities immediately grab our attention. Just about all of us are quickly drawn to the conventionally beautiful, for example. But these attention-grabbing, shiny qualities, the data suggests, make no difference to our long-term romantic happiness. The data suggests that single people are predictably tricked by shininess.

• A Wired report