the "everybody knows" fallacy

To communicate effectively with data, it’s important to make our charts, slides, and reports as clear as possible to our intended audiences. In order to achieve that goal, we have to remember that what seems self-evident, obvious, or “common knowledge” to us might not be common knowledge to others. When we don’t account for what our audience might not know, we may create unnecessary resistance and unintentional discomfort, making it harder to gain support for our recommended course of action.

Today we are bringing you a special guest post by Miriam Dickler, who has written an excellent article on this very topic. An expert in many communications specialties as well as a trained facilitator and mediator, Miriam has dedicated her private sector career to bridging divides between organizations and communities through thoughtful engagement, education, and strategy.

Here’s “The ‘Everybody Knows’ Fallacy,” by Miriam Dickler:


If you train with me, it is almost inevitable that you will see this slide.

The “Everybody Knows” Fallacy: what you think of as “everybody” is really a tiny subset of who “everybody” really is.

The “Everybody Knows” Fallacy: what you think of as “everybody” is really a tiny subset of who “everybody” really is.

There is nothing that grinds my gears quite like the phrase "everybody knows." It is deployed by all kinds of folks in all kinds of situations and is very rarely, maybe never, true.

The thing about everybody knowing something is that “everybody” is a finite group of people. When we say "everybody," what we mean is, "everybody I talk to." 

That subsection of "everybody" can feel pretty significant. Not only does it include your partner, coworkers, best friend and neighbor, but all of your Facebook friends and Twitter followers. The problem, when we zoom out and look at the world at large, is that our spheres are never as wide and inclusive as we would like to believe they are.

One of my go-to examples of this fallacy is a hypothetical pothole on the street outside of your home.

This pothole annoys you every day. You have to swerve to miss it, the dog keeps trying to play in water that accumulates in it, and at least once a day someone hits it with a tire and it makes a terrible ruckus. It's an eyesore, it's a nuisance, it's a danger and EVERYBODY KNOWS it's there! So why isn't your local road crew getting on it already??

This is the question that gets posed when this hypothetical you is on the phone with a hypothetical city hall. "Everybody knows this pothole is out here causing trouble and YOU haven't done anything about it, even though that's your job, because [insert whatever reason fits the narrative best: the city dislikes your neighborhood; the crews are lazy; the budget is being squandered; whatever]."

Maybe—maybe—one of those things is the reason that nobody has come out to patch the street. Or maybe it's that "everybody" actually doesn't know that it's there. You know, your neighbors know, and everyone who you talk to about it knows...but does that include road crews? Do city vehicles often travel your road? Would one of them have called it in? Until you picked up the phone in a pique, had anyone reported the problem?

"Ah yes," I can hear my government, business and nonprofit clients saying. "Yes, so often people believe us to be mind readers and then get mad when we cannot read their minds. Thank you for affirming this for us!"

Not so fast. It is as likely, if not more likely, that organizations are playing fast and loose with what they assume everyone knows, because within the organization everybody does know.

Here is a true story. Soon after I had taken a position running a comms office, I was handed a rough draft of a flier. This flier was very proud to announce a road opening. The design and build of the road, it told me, had ensured the road was multimodal!

I looked at the engineer who gave me the flier and said, "This is great, but use something other than "multimodal." It's not common language." The engineer scoffed back at me, "Everybody knows what ‘multimodal’ means." 

Engineers are some of my favorite people, but in cases like this, most of the people with whom they have discussed something are also engineers. I have absolutely no doubt that all of the engineers did know what multimodal meant. But the flier was for the general public.

I invited the miffed engineer to walk out of my office into the hallway with me, where I asked the first person I saw if they knew what multimodal meant. We were in city hall, a place that had a pretty high potential of presenting us with someone who absolutely did know what it meant in this context. But, no, the first person I asked didn't know, neither did the second, or third.

This isn't a story about a time I was right. It’s a story about the importance of stepping out of our bubbles to ask someone if we are being clear...and the need to trust them when they tell us we aren't.

Common language is not common because people are stupid, it is because we speak different dialects. Every profession, hobby and organization has its own jargon, acronyms and shorthand. When we spend all of our time in those shared spaces, we lose sight of the fact that most people are not there with us. Worse, many people will pretend to know what something means in order to not (in their estimation) look stupid.

If there are three things I want you to take away from this, they are:

  1. Don't overlay your experience onto others. You have a unique frame of reference. Expecting all people to share that will only cause you (and others) frustration. Widen your community and reach out to folks you may not have previously included.

  2. Lose the jargon. I've written about this before, but it bears repeating. Spell out acronyms, define terms, explain context.

  3. Don't be afraid to ask questions. Often, a group of people simply needs one person to say, "Can you define that?" or "I'm unfamiliar with that acronym, what does it stand for?" Even if you know, there is likely someone who doesn't. Come to their rescue!


Miriam Dickler is the owner of Rebel Tree, LLC, a communications consultancy located in Charlottesville, Virginia. Before launching her own firm, Miriam led local government communications teams through calm and crisis for close to two decades. You can learn more about Miriam and Rebel Tree at RebelTreeLLC.com, or contact her directly by email at miriam@rebeltreellc.com.