Facebook Knows Way Too Much About Relationships, And Now They Are Letting Us Have A Peek

Owen Poindexter
Facebook knows everything about you that you care to tell them, and probably a lot more. More interesting than what they know about you or me, however, is what they know about us.

Facebook knows everything about you that you care to tell them, and probably a lot more. More interesting than what they know about you or me, however, is what they know about us. Population-wide data drawn from Facebook, while not fail-proof, is more accurate and compelling.

For Valentine’s Day, Facebook’s data team is releasing a series of findings on love and relationships. Here is some of what we’ve learned so far.

1.       How much does religion matter in a relationship?

Let’s imagine a world in which people coupled up with no regard to their partner’s religion. That’s the world imagined by the x-axis in the graph below, which Facebook calls “expected same-religion relationships.”

In a country like India with one majority religion (Hindu) but large populations of other religions, you would expect a religion-blind population to end up in pairs with matching religions a little over 40% of the time. In reality, people end up with a same-faith partner over 90% of the time (shown by the graph’s y-axis).

A quick glance at the data shows that people partner off within their own faith much more than they branch out. Spanish people, with the highest percent of interfaith relationships, still end up in same-religion pairings about twice as often as would be expected if it was all random.

With all this data, keep in mind that this comes from what people post on Facebook. People who put their religion on their profile are more likely to be more religious, more concerned with finding someone of that faith, and more likely to spend time at religious services.

2.       Which cities are best for relationships? For casual dating?

Some cities seem to be more about finding a partner, and others are more into dating without pairing up. Colorado Springs, Louisville and three cities in Texas—El Paso, Fort Worth and San Antonio—have the highest rates of partner formation, while the lowest are our country’s center for tech, politics, culture and entertainment (San Francisco, Washington, New York and Los Angeles). Perhaps cities where people come for a specific purpose make it harder to find a partner and/or that draw skews the gender ratios.

3.       How likely are you to stay in a relationship?

Facebook looked at relationships longer than three months (since going Facebook-official, which means most of this data set actually starts at closer to six months in), and how long it took for the relationship status to go back to “Single.”

As relationships progress, the chances of them ever ending drops. In fact, the data already starts with a fairly high stability rate, with no relationship examined having higher than around a 10% chance of breaking off in the time that Facebook has been spying on them.

4.       What’s the story with age difference in relationships?

Age differences in relationships are something that a lot of people have intuitive ideas about, and Facebook put those ideas to the test.

As we can see, age differences between partners get larger as people get older. The average age gap between two partners is around two years at age 20, but by 35, separates out to 4 years for straight couples and about 7 for gay couples. For whatever reason, gay couples show a larger age gap from the get-go. This may be simply due to the fact that there are fewer of them, and so gay people looking for love cast a wider net in terms of age range.

And here’s an interesting question: does gender inequality lead to larger age gaps among straight couples?

Yes, it does:

It’s not a perfect correlation, but there’s definitely a relationship between the two factors. The x-axis measure, “Global Gender Gap,” is a statistic calculated by the World Economic Forum based on gender inequality in “economic, political, education- and health-based criteria."

Scandinavian countries show equality between men and women on these benchmarks, and they have an average relationship age gap of around 2 years.  Turkey and Egypt are on the opposite end of the gender equality spectrum, and their average age gaps are over 3.5 and 5, respectively.


While there are obvious issues with this data—only includes Facebook users, only includes what they post on Facebook, etc.—it is a rare treat to be able to glimpse this enormous a data set. Social scientists usually have to struggle to corral a small fraction of what’s presented here. Hopefully Facebook will continue to use its data for more than profit, but to add to public knowledge as well. If you love this stuff as much as I do, go check out Facebook's data page and read the full posts, which have a lot of data I couldn't fit in here.