Nudgespotting: When Nudges Backfire

By: Jamie Kimmel (ideas42)

Welcome to Nudgespotting! Every other week we'll take a quick look at some real-world nudges, with a healthy dose of commentary and behavioral references.

This week we turn our behaviorally-focused eyes to well-intended nudges that backfire, either with an opposite of what was intended effect, or some other unforeseen negative effect.


How Many Users Donate to Wikipedia?

One of the most used principles from behavioral science is the descriptive norm. A US-based company called Opower utilizes this principle throughout their products, which are primarily redesigns of electricity bills that show a comparison of a household’s energy use to its neighbors. This small bit of information motivates a 2% average decrease in energy use (notably, that change happens in the absence of financial incentives). 

Because the logistics of implementing a descriptive norm nudge into a product seem quite simple, it has been replicated many, many times. Which brings us to our first example: a Wikipedia donation page that uses descriptive norms.

Reader Erin Brady, Professor of Human-Computer Interaction at IUPUI, pointed us to this example. In early 2015, Wikipedia began testing new ads on its website to bring in more revenue via donations. The central theme of these messages is around two facts: Wikipedia has 450 million users, and less than 1% of those readers donate to the site.

Problems arise, however, when we look at evidence from behavioral science around the use of normative statements. This one from the context of voting

The fact that many citizens fail to vote is often cited to motivate others to vote. Psychological research on descriptive social norms suggests that emphasizing the opposite—that many do vote—would be a more effective message. ...Practically, the results suggest that voter mobilization efforts should emphasize high turnout…. More generally, our findings suggest that the common lamentation by the media and politicians regarding low participation may undermine turnout.

So it’s possible that, by pointing out how few donate, these Wikipedia messages may actually be counterproductive.


Do Dual Flush Toilets Save Water?

Many homes and workspaces in the developed world now come with dual-flush toilets. A 2015 study from the Netherlands, for example, states that about 75% of new homes have dual flush toilets, while even about 30% of “older homes” have them. This is widely viewed as an obvious positive – a prevalence of water-saving technology will simply lead to an increase in water savings.

Which takes us to our second nudge, coming from reader Nick McColey of STAR Education, on dual flush toilets:

Nick had this to say about the user experience of the dual flush: “If it’s the up/down one (as in the above image), I usually just push it down. I don’t understand why they would expect anyone to pay enough attention to pull up on that handle. We’re all already in the habit of pushing down with these types of handles, anyway.”

He has a good point. There’s some evidence that dual flush toilets may actually lead to an increase in water use:

…the installation of dual-flush toilets may lead to significant increases in the number of flushes per day. …In this context, the interaction between habits and technologies is crucial, as for some appliances the potential rebound effect due to behavioral changes may lead to lower than expected water efficiency gains from the introduction of water-saving technologies.

This is why the design of any technology that's meant to be used by people should be integrated, in some way, with a solid understanding of human behavior. 


Tell Me to Do Something and I'll Do the Opposite!

Our final backfire comes to us from Owain Service, Managing Director of the Behavioural Insights Team (BIT). 

Not so much a nudge, but still demonstrative of an important principle in social psychology: reactance. That is, people may react negatively to commands or restrictions in freedom, which then simply exacerbates the original negative behavior (cup stacking!). 


These examples demonstrate two very important concepts. One, that even well-intentioned and well-researched designs may fail. And two, that we can't actually know how well a design will work until it's been tested. 

Have you spotted a nudge in the wild? Feel free to send them our way by:
•    Emailing us at
•    Tweeting us at @MisbehavingBlog

We might feature you in an upcoming post!