How does facebook come up with friend suggestions

Facebook's suggested friends feature takes snooping to a whole new level. Next time you have a harmless stalk or leave your location services on, know Facebook's many eyes are watching you...

‘People you may know’ is a phrase that seems harmless, if a bit formal - ‘Oh come to this party! There’ll be loads of people you may know there!’ - but in the last few years it’s become synonymous with that creepily accurate Suggested Friends carousel featuring people who yes, you do know but, my god, how does Facebook KNOW you know them?!

Facebook’s official line on this, on their help page, explains that they make selections for your Suggested Friends based on ‘mutual friends, work and education information, networks you’re part of, contacts you’ve imported and many other factors’. It’s the ‘other factors’ that are the most interesting, considering how goddamn vague they are.

Just having a brief scan over my own current suggested friends, there are at least three people there that I haven’t met, I’ve never worked with, we didn’t go to the same school, I have no mutual friends with and they’re not in my contacts. One of them is someone I’m fairly sure, after doing a quick search on other social media sites, is currently seeing my ex. So why is she being suggested?! Is this to do with the ‘other factors’ Facebook mentions? I don’t know her! Were we once in the same cafe? Has she, completely understandably, been stalking me? Have we finally found the definitive answer to how you can tell when people have looked at my profile?!

Are your suggested friends based on where you’ve been?

In one of the best cases of 'ER, NO I DIDN’T MEAN THAT, SHUT IT DOWN' Facebook revealed in 2016 that location data was one of the factors in suggested potential friends, before days later retracting it and saying they absolutely didn’t. Cool.

There were a number of slightly worrying reports of how eerily accurate the supposed algorithm is; ‘Seriously, I’ve had enough reporters ask me, freaked out, why Facebook is recommending their protected sources’ tweeted Violet Blue, a reporter on cybercrime.

If true, it also means that Facebook uses similar technology to the NSA.

During an investigation, Fusion) found a load of anecdotal evidence pointing towards location services being used. One example was a man who had attended an anonymous gathering for suicidal teenagers, and had then seen one of the teenagers he didn’t have any contact with other than being in the same place, popped up as a suggested friend. They approached Facebook who said: ‘Location information by itself doesn’t indicate that two people might be friends, that’s why location is only one of the factors we use to suggest people you may know.’

That was on Monday, and on the Monday night - when Fusion had published an article, understandably, explaining how this is a privacy clusterfuck - Facebook immediately retracted it. The statement was changed to the fact that location services had been trialled a year earlier, but weren’t one of the very vague ‘other factors’ described on the help site.

The journalist in question described ‘repertorial whiplash - I’ve never had a spokesperson confirm and then retract a story so quickly.’

So, er, basically it’s highly likely your location services are informing your suggested friends. Call it, y’know, a feeling we have.

One way to stop this is to change the location settings on your phone, or get rid of the Facebook app and use it on good ole Safari. Other browsers are available.

Are your suggested friends based on who has looked at your profile?

There is no hard evidence that someone else’s activity affects your page - and a Facebook employee was fairly clear on their stance in a recent Quora thread:

Thanks for your illuminating and rich response, Peter. But I find it difficult to believe that, when trying to create the perfect suggested friends list, Zuckerberg wouldn’t have wanted algorithm kick into gear when you search for someone, or if someone searches for you. Because that’s the purest way it can tell if you want to be friends, surely? Plus, there are just too many anecdotes to ignore.

‘I recently viewed someone who I haven’t been in touch with for many years and who I didn’t want to be in touch with,’ says one anonymous user on Quora. ‘Two weeks later I had a friend request from that person. I have no common friends and this person is far removed in my network of friends. Unless this person suddenly remembered me after almost twenty years since I have contacted them, then I have no other explanation.’

In a recent Vice investigation into how this suggested friend list happens, David Liben-Nowell, a computer science professor at Carleton College who studies the structure and evolution of social networks said:

‘My hunch is that [Facebook is] using names you've searched for or profiles you've viewed to suggest friends to you. It would almost be silly for them not to: if you've shown an interest in a person while using Facebook, then you've as good as told Facebook that you might want to have some kind of relationship with them.’

Agreed - it does make a whole lot of sense, if they’re trying to make the friends they suggest as accurate as possible. And there’s also some fairly compelling evidence pointing to the fact that the friend grid works off the basis of who is looking at your profile, so why not suggested friends? I mean, that makes even more sense, if you think about it.

Are your suggested friends based on your phone contacts?

This one is a definite yes. In one of the many app updates, you will have inadvertently synced all your phone contacts to Messenger. And if you’ve allowed Facebook to sync your phone contacts, then it’s going to suggest you connect to them online. It can be freaky, though, if you don’t realise you’ve put people in your contacts because you’re drunk, then they get suggested back at you.

‘Somehow my suggested friends list is always chicks I have had one night stands with,’ says a Reddit user who says words like ‘chicks’. ‘Facebook somehow looks through my contacts on my phone and uses their phone numbers to suggest it. It's kinda creepy when you see a girl who you met one time and didn't even know her last name, but somehow they are suggested for you.’

An easy way of getting rid of this via the Facebook app on your phone - go to settings, and scroll down until you see ‘Sync Contacts’. Hit ‘remove Facebook’. Done. Removed. You can also do it via this link here.

And check out the box that comes up as you’re about to remove the contacts:

‘If you choose to remove your imported contacts, friend suggestions for you and your friends may become less relevant’. YEAH MATE. THAT’S SORT OF WHAT I WANT COS YOU’RE CREEPING ME THE F OUT.

Are Facebook friends suggestions based on other third party apps like Tinder?

The official line on this is no. In fact, it couldn’t be any more a ‘no’ if they tried, as they state on site: ‘We do not use cookies from third-party sites to generate or rank People You May Know’. Well there you are then.

However, if you’re getting a bit freaked out by the fact that Tinder matches/people you’ve Bumbled have suddenly started cropping up, then you’re not alone - it’s been a bit of a recent thing. And if you don’t have their number in your phone, then how the hell do they know this if they AREN’T getting it through Tinder?

Well, it’s likely that your Tinder match will have also tried to stalk you on Facebook and, while Facebook claim they don’t suggest friends who search your name, we reckon they probably do.

But the other, less speculative, solution is that you have their number on your Whatsapp contacts. Because Whatsapp bought Facebook, so if you’ve been ‘sapping, and you haven’t un-synced your Facebook contacts (as above), then do that immediately.

Exhausting, isn’t it?

One last helpful tip - if you block your ex, then they won’t show up on your suggested friends list. So if you have any particularly triggering people from your past, then it might be worth taking a deep breath, having a dram of whisky (or, like, a glass of juice) and doing the deed.

Oh, and you know how you can specify people who you don’t want to come up in that horrific On This Day feature? They won’t come up in your suggested friends either - which might be a good idea if you don’t want to all-out block someone, you just don’t want them popping up all the time.