Deaf Dogs and Psychological Nudges

Daniel Brown
3 min readAug 31, 2020


Photo by Avi Richards on Unsplash

Driving in Vermont, I came across a brilliant (though likely unintentional) psychological “nudge.”

It was traffic sign of sorts nailed to a tree in someone’s yard. The sign read

Drive Slowly
Deaf Dog

Now, before reading further, I encourage you to ponder those words for a few moments. (I certainly did.) Would I really need to slow down for a deaf dog? I guess it’s a good idea. I certainly wasn’t speeding but, whatever speed I was going, I decreased it while glancing around for a dog that seemed unaware of the car. Then I thought about it a bit more… a deaf dog? I could understand needing to slow down for a blind dog and certainly for a deaf and blind dog (which probably shouldn’t be wandering around freely outside anyway), but a deaf dog?

Regardless, herein lies the brilliance of that sign — it worked. By the time I had sufficiently processed what it said, I was three blocks down the road and likely well out of the range of the dog in question (if it existed).

The key here is that the sign worked, not because of what it said, but because:
1. It cast doubt in my mind about whether to slow down for a deaf dog.
2. It made me glance around, slightly curious if I could spot a deaf dog.
3. The cognitive effort in determining the validity of the sign led me to slow down while I thought about it. I gave the sign the benefit of my doubt.

It makes complete sense that requiring people to use the “system one” (the slower) portion of their brains achieves the desired effect.

My grandfather had a similar tactic. He did much of the repair work on their church and, after painting any surface, he would hang “WET PAINT” signs, but he’d hang them upside down. He would also occasionally make signs that said “PET WAINT” (sic). People were quick and eager to point out the intentionally induced “errors” in his signs, but both methods achieved the desired effect; the difficulty in reading the sign meant people actually noticed them. (This simple trick is helpful when proofreading your own work. Just change the typeface of the document to Comic Sans. The pain of reading that typeface makes typos much clearer.)

I’m also reminded of the rather effective signage near an electrical closet that said, “DO NOT ENTER! You are likely to be killed and it will be a very very slow and painful death.” Apparently, just telling people that something will cause death isn’t sufficient. You need to tell them, not just about being dead, but how might go about becoming dead.

Then there’s the man in the U.K. who climbed into a lion cage. While it’s tempting to think “well, why didn’t they put up a sign telling people not to climb into the cage?” the answer from the brilliant English comedian Phil Jupitus is “BECAUSE IT’S A LION’S CAGE!” Just the fact that it is a lion’s cage should be enough information for anyone considering entering it for whatever reason. But perhaps this isn’t quite enough information or of the wrong kind. Like the electrical closet, the notion of serious bodily injury up to (and including) death might not be enough to dissuade. Perhaps the occasional individual needs to be reminded that lions attack, kill, and eat other animals and they find humans — especially ones in their enclosed cages — just as tasty and not as feisty as other animals. We’re also quite easy to catch.

When attempting a shift in human behavior, a direct approach is usually the best one, but sometimes a bit of subtle cognitive work can be far more effective.