If the nudges we plan are not properly designed and implemented, there is a big risk that those nudges may actually backfire on us. This tends to happen in social-media campaigns, where the messages that we try to communicate are not properly embraced by our audience. To understand this we must differentiate the circumstances under which the descriptive norms (what people usually do) and the injunctive norms (what people usually approve or disapprove) work.
It’s clear to us that the messages from these campaigns are well-intended, but it is not the intentions that we process in our minds, but the message itself! and an incomplete message can easily turn into an incorrect message; for example, when we say that “a lot of people avoid thinking of Pink elephants” or “a lot of people don’t think of Pink elephants”, there’s an implicit normative message of “a lot of people think of Pink elephants” that’s also being given, implying that thinking of Pink elephants it’s a problem, but it’s also something socially-frequent.
Descriptive norms affect the perception of behaviours that are usually carried out; they are anchored to the behaviours of other individuals, and it’s easy to adapt to this norms without much analysis, as we tend to assume that if everyone else is doing it, and they’re still alive and kicking, then it should’t be as bad as it sounds. Even other animals imitate others behaviours in a natural way, like bird flocks or fish shoals.
On the other hand, injunctive norms involve the perceptions of behaviours that are socially approved or disapproved; they are based in the moral understanding of social norms, these include what others probably approve, but there’s a need for further analysis to carry it out satisfactorily, unlike the descriptive norms, indicative norms need to activate system 2 in out mental decision-making process. Much investigation exists indicating that both types of norms can motivate people to take action, that means that we are prone to do what is both popular and socially accepted.
When we are trying to modify peoples’ behaviour in a situation like polluting the street or stealing, we need to make a clear distinction between descriptive and injunctive norms. If we want our friend Irrational-Cosi to stop polluting our street, we must not give him the wrong message by telling him what most do to stop polluting, instead, we should tell him which behaviour is socially approved or disapproved in that situation. To test this, Cialdini, (2003) made an experiment in Arizona’s Petrified Forest National Park.
The visitors of the Arizona’s Petrified Forest steal approximately more than one ton of wood every month. To fight this, park officials put a sign with the message “Your heritage is being vandalized every day by the theft of petrified wood of 14 tons a year, mostly a small piece at a time.” Even though the officials tried to diminish wood theft by describing the size of the problem with the message in the sign, they were, at the same time, notifying visitors about the behavior of past visitors. Instead of focusing in the descriptive norm, it would’ve been better to design a sign with an injunctive norm focused on the socially disapproving the behaviour of stealing wood.
To test this hypothesis, marked pieces of wood were secretly placed along the pathway of park visitors. During five consecutive weeks, selected pathways had signs alluding to normative or injunctive norms related to the park’s petrified wood theft. The sign with the descriptive norm displayed “Many past visitors have removed petrified wood from the park, changing the natural state of the Petrified Forest.” This sentence was accompanied by an image of three visitors taking a piece of wood. In the other treatment, the sign with the injunctive norm displayed “Please don’t remove petrified wood from the Park, in order to preserve the natural state of the Petrified Forest.” This sentence was accompanied by an image of one lone visitor taking a piece of wood with a red circle and a bar over his hand. As expected, the message with the descriptive norm resulted in an increase in wood stealing (7.92%), compared to the injunctive norm message (1.67%). The funny thing (or sad actually) is that both messages resulted in an increase of theft amongst visitors!
This is why whenever we want to change a behaviour, we must analyse thoroughly all the elements behind the behaviour and design an effective nudge, otherwise we could see all our hard work backfire into negative results. If you’re designing a social-media campaign you need to avoid messages that suggest that a social action is disapproved, but widely accepted. Normative messages generally have higher impact when both descriptive and injunctive norms work together, rather than on their own or competing against each other. When joining two sources of normative motivation a higher social influence can be achieved. The normative persuasion, and thus the results, of the campaigns that are able to align descriptive norms with injunctive norms will be much higher. If we give correctly aligned messages to our friend Irrational-Cosi, do you think that he would stop polluting our street?