"Guys, look at this ridiculous
. It says that only 53 per cent of our friendships are mutual, which is to say that half of the people we like don't like us back.
"How did they get that one so wrong?! Don't you think it's funny, guys?
Your peals of nervous laughter echo emptily around the room as you fall silent. You look up from your screen.
Your colleagues - your friends? - are gone. They have taken their personalised mugs. Yours plain and white, remains. Amy's freshly-vacated wheelie chair squeaks on its axis before coming to rest.
Well, at least it's quiet now, you think. And so, slowly, sadly, you read more about the study, which was conducted by Massachusetts Institute of Technology's Alex Pentland.
"These findings suggest a profound inability of people to perceive friendship reciprocity," said Pentland, no doubt stabbing names out of his Christmas card list as he spoke.
He had asked 84 students on a business management course to rate how close they felt to each other, on a scale of zero ("I do not know this person") to five ("This person is my best friend. Look, matching bracelets!").
Ninety-four per cent of the students thought their feelings would be reciprocated, but their friendship ratings were matched just 53 per cent of the time. This isn't the first time such an effect has been observed; scientists have hypothesised that we overestimate the strength of our friendship with more popular individuals. Ouch.
By now, your chuckles have been replaced by dry sobs. If only I'd known, you think, that my relationships were built on sand! If only I had been told earlier that there are in fact seven ways to tell whether your friends actually like you!
Read and learn...
You're in the picture
Literally. If you're always put on snapping duty - and never asked to appear in group shots yourself - it's not a good sign, especially if the girl with incurable hoverhand has made it in. Take a look at your friends' Instagram pages, if you dare, and cross your fingers.
You use a smiley face emoji in your conversations? Cool. Enjoy floating in the interminable icy orbit that is peripheral friendship. You use the poo emoji instead? True pals.
Secrets and secrets
A paper called "Girl Talk", produced by Oxford's Social Issues Research Centre, looked at "the new rules of female friendship and communication" and found that 70 per cent of men and women agreed that they wouldn't tell a secret they had been told not to tell.
But a third of the same respondents agreed there were different kinds of secret, some they would pass on and some they wouldn't.
"There are secrets and secrets," explained one of them. How do your friends treat your classified information? There are friends and friends...
They know your weaknesses
...and they hound you mercilessly for them. Because what are friends for, if not to dredge up time and again those tales of drunken humiliation? That time you walked to a kebab van in bare feet, or vomited in a handbag? True mates know your vulnerabilities and bad points and love you anyway. Even if they show it through mocking.
They don't make an effort
Yeah, we all play the game of looking presentable at work and when socialising, but it's just that: a game. Deep down, we're all jogging-bottom slobs, and the sooner in a friendship we come clean and stop pretending, the longer that friendship will last. A friend for life is someone who's seen your threadbare pyjama shorts and doesn't judge.
You get the first invite
We all know how Facebook party invitations work: first come the key players, the old faithfuls, the bosom friends. Once they're confirmed, the next batch is invited: those whose attendance was non-essential; who didn't spring to mind the first time but will serve to bulk out numbers. You weren't one of the initial lot? Bad news.
They know your pizza order
That'll be a large Veggie Volcano with stuffed crust and garlic dip. But you knew that.