Social Norms in Action

From a reader named Stephane:

Very recently I drove through a couple of small villages in the northwestern part of Belgium (near the border with France). A couple of road signs caught my attention. When you reach a village there’s a sign (in Dutch) saying “here, X percent of the drivers stay within the speed limit.” Then when you reach the next village there’s the same sign except that the percentage is different. Usually it’s around 90% (87% in one village, 91% in another, etc.).

I don’t know how they collect the data or even if the numbers are real. I also wish I knew the trends, how often they change the signs, how many villages participate in this safety initiative, etc. Then I wondered: where does this idea come from? Have you heard of anything like this before? If yes, is this effective to slow cars down?

Why yes, I have heard of such a thing. In a podcast called “Riding the Herd Mentality,” we discussed the use of “social norms” to bend behavior to one’s liking. One interesting example I’ve seen recently while visiting in Chicago: big signs over the highway that tell you how many people have been killed in motor-vehicle accidents so far this year.

Have any other examples worth sharing?


In Georgia they have something similar except it is "seatbelt usage". It gives an actual % and there goal fir next month. I doubt that the numbers are real, it is just a way to get people to buckle up.

Richard Lowery

An example from the UK. On buses in the County Durham town of Darlington there were adverts stating that 8 out of 10 teenagers did not drink alcohol, or 9 out of 10 youngsters did not engage in anti-social behaviour.

Nb - these adverts appeared a couple of years ago, and I can't remember the exact proportions that were used - but you get the idea.


I taught at a high school that did something similar. The students completed a survey on social behavior. A few months later, the admin had posters that said things like, "xx% of [our] High School Seniors do not drink regularly on the weekends" and such.

Given that high school students are more likely to do something only if other people are doing it then I have a feeling it may have had some impact.


"“xx% of [our] High School Seniors do not drink regularly on the weekends”"

This is probably not effective - or even counter-effective - if the actual numbers - roughly 10% from my memories of high school - are used. And would be even less effective if realistic qualifiers were added, as for instance "but 90% of those 10% were sitting home wishing they'd been asked to the parties".

Seems there's a difference between measuring social norms, and social engineering by trying to create the false impression that your desired behavior is actually the norm.

Eric M. Jones

In Mexico there are "topos" also knows as speed bumps. These often appear to be made by the locals to keep people from speeding through their villages. Since speeds on Mexican roads are often...ignored...these topos often come as a devastating surprise to the unwary driver.

Even when you are careful, you'll see and slow down for oh... 99% of them. But that 1% you miss is a memorable experience.


They're actually called "topes", not "topos". Those are usually the least of your worries, however. The biggest problem is all the "baches" (holes) all over the pavement. Many a tire has been punctures going over a bache.


Those signs that list the number of fatalities on a road always seem quite low to me, but probably quite high to those setting them. '5 deaths in 3 years' might be a lot for a short section of road, but to me it says 'pretty low chance of dying in the next five minutes'.


When my wife and I hiked the Hanakapiai trail on the Na Pali coast of Kauai, Hawaii on our honeymoon (yes, it was awesome!), there was a wooden sign with tick-marks supposedly indicating how many people had died by venturing off the trail (there were 43 marks). I doubt if they actually bother to update it or even if that many people have died but knew it was a tactic to scare people into staying on the trail. It also seemed that people who saw it would scratch in their own tick-mark. Either way, it's a pretty dangerous and rigorous trail in its own right and we had no plans of venturing on our own. So I'd say it worked! :-)

Molly Sturtevant

My college, Whitman College, had a social norms campaign for alcohol use and created and posted signs around campus with percentages of how many of certain groups (sorority members, freshmen, rugby players, etc) used (or abstained from) alcohol. Many students made fun of the posters (to look cool, I presume), but alcohol use dropped in several of the groups, if I remember.


I think I want to avoid the herd mentality of the herd that has died.


Way to go. A well known insurance company did this with their claims offices (of varying sizes) some 40 years back. They would publish an internal memo of claims paid per hour for each of the 30+ offices every month. So imagine being on top, that manager would feel a bit compelled to at least maintain his relative position..... and so on down the line.


"Most KU students have 0-5 drinks when they party".

Wasn't too sure that one helped much.


Many restaurants list suggested tip amounts on the receipt:
15% = XX
20% = YY
25% = ZZ
This presentation sets 20% as an average/expected tip, and one should not even dare to consider 14%.


In Japan, there are loads of small police stations, manned by one or two officers. As far as I can tell, every such small station carries a sign showing how many deaths and injuries have been reported/recorded. People usually do not know the area the statistics are supposed to cover or since when the date has been collected - presumably the area covered is the jurisdiction of the police head quarters the particular station belongs to and the number is year-to-date. Anyhow, you can easily get used to the sight of those numbers and changes in numbers stop meaning anything pretty soon. I seriously doubt it deters anything but they keep doing it.

Derek P

Next sign: There is a 7% likelihood that the previous sign will have an effect on your driving.


Yeah, we have billboards like this on every road and highway of India, but they don't work... Why? Because no one believes advertising anymore!


At Australia's greatest horse race day, the Melbourne Cup, the public set up picnic spots on large grass lawns to enjoy the action. However, as they crowd in, this leaves little room for people to move about, to and from exits, etc. So the ground staff simply painted paths - 2 white lines - on the grass. There are no signs saying keep off, don't set up here. People register it as a path subconsciously - even thought it's still grass - and don't sit there.