Social scientists have long sought to explain why people donate resources for the good of a community. Less attention has been paid to the difficult task of motivating the first adopters of these important behaviors. In a field experiment in Nigeria, we tested two campaigns that encouraged people to try reporting corruption by text message. Psychological theories about how to shift perceived norms and how to reduce barriers to action drove the design of each campaign. The first, a film featuring actors reporting corruption, and the second, a mass text message reducing the effort required to report, caused a total of 1181 people in 106 communities to text, including 241 people who sent concrete corruption reports. Psychological theories of social norms and behavior change can illuminate the early stages of the evolution of cooperation and collective action, when adoption is still relatively rare.

INTRODUCTION

Why do people donate time, money, or other resources to their communities? Scientists view this question about community-minded behavior as part of a broader question about why humans cooperate, which sets apart large-scale human behavior from the behavior of other species (1). Research has uncovered several factors that drive and constrain community-minded behavior, including expectations of paybacks (2) and of punishments for free riders (3), internalized decision-making tendencies that favor cooperation over selfishness (4), and perceived social norms (5). A rich tradition of research on the evolution of collective action for public goods provision was inspired by the pioneering work of Ostrom (6), but few studies in this tradition focus on how community-minded behaviors are initially adopted. Community-minded behaviors that are rare (because they are novel or, for whatever reason, are not widely adopted) may carry special costs and risks. These costs and risks accrue from the fact that people have difficulty choosing and acting on alternatives to the status quo (7, 8), people’s contributions may not be matched by other community members without coordinated punishment of free riders (3, 9), and people may perceive social, legal, or safety risks associated with being one of few to participate. Understanding why people would sacrifice resources for their community, particularly when it is not socially recognized as a common or desirable behavior, is important for understanding the full evolution of a collective action strategy (6, 10).

Learning how community-minded contributions are adopted and become normative is also pragmatically important because voluntary community contributions are often encouraged in contexts where government or private sector initiatives are infeasible or unsuccessful. For example, reporting social or political problems via text message is a recently invented solution used by a growing number of political activists, civil society organizations, and technology experts (11). Initiatives in countries like Kenya, Haiti, and India have asked people to contribute information about local violence, natural disasters, or corruption to help other citizens navigate crises and to identify areas in need (12, 13). Studies of technology adoption show that once a certain threshold of new users is achieved, bandwagon effects, herding, and information cascades can spur new behaviors to become widespread in a society (14, 15). However, the success of these initiatives depends, as a first step, on persuading an initial group of people to try a behavior that is outside of the status quo.

The current study addresses this first step, of how to persuade an initial group of people to try a new form of community-minded action. We identify two major barriers to adopting new actions: the perception that no one else will join (a problem of social norms) and minor logistical or technical barriers (a problem of personal and structural capacity). Psychological theories of social norms and behavior change offer ideas for addressing each barrier—specifically, mechanisms for influencing individuals’ perceptions of social norms, and small interventions for increasing individuals’ personal capacity, given structural and cognitive constraints.

Psychological theory defines a perception of a social norm as an individual’s perception of how widespread or desirable a behavior is or is becoming within the community (16, 17). Research suggests that norm perception is a strong motivator of human behavior (18). For motivating rare behaviors, perceptions of a norm can be influenced even before changing the actual rate of the behavior in a community (19). Studies suggest that this is possible in part because people overgeneralize from the public behavior of role models to their perception of the overall community norm (20, 21). Role models who influence norm perceptions can be people in one’s community who are high status (22, 23), who receive lots of attention (20), and, in some cases, who break with tradition (24). However, people can even use fictional characters as role models, such as characters in a soap opera (25). Thus, one mechanism for changing norm perceptions is to highlight the behavior of role models, real or fictional (19).

Psychological theory on behavior change also highlights the importance of removing minor but psychologically important barriers to a behavior, using a “nudge” (26). A nudge—such as a reminder (27) or a new default (28)—helps a person to accomplish a behavior toward which he or she is positively inclined by removing barriers to the behavior. While this insight may seem intuitive, behavioral research has demonstrated that what may seem like a materially insignificant cost, such as memorizing a number or filling out a form, can actually be a psychologically large barrier given constraints on individual cognitive or motivational capacity (26). A wealth of studies show that using nudges to remove minor barriers significantly increases rates of consequential behaviors like showing up to a court date (29), successfully enrolling in college (30), and voting (31).

Thus far, psychological theories about norms and behavior change have been successfully applied in Western democracies to improve low rates of community-minded behaviors. Using a large-scale field experiment, we evaluate these two psychological theories in a non-Western context where activists sought to encourage the rare behavior of corruption reporting. In Nigeria, reporting corruption to nongovernmental agencies is part of an envisioned citizen-driven campaign to reduce the country’s endemic corruption (32). Activist groups hope that large numbers of people will report their experiences with corruption, which would be used to write advocacy reports testifying to the widespread nature and negative effects of corruption on the population. However, citizen corruption reporting is extremely uncommon in Nigeria. Previous efforts to encourage reporting have been uniformly unsuccessful, regardless of the recipient of the reporting and regardless of the technology used. Nationwide campaigns via phone, text message, and the internet have elicited no more than 140 reports per year, out of a population of 174 million (33, 34).

The failure of previous corruption-reporting campaigns in Nigeria cannot be attributed to a lack of concern about the issue, since Nigerians consistently name corruption as one of the top problems facing their country (35). Our pilot research in Nigeria, including a survey of 345 randomly sampled individuals in the four states where our study took place, indicated that just under 80% of citizens believe the police, civil servants, and their state governments were corrupt. Eighty-three percent reported being angry they had to pay bribes, and 60% reported being very angry. Our research also suggested the importance of the two barriers to reporting. With respect to perceived norms of reporting, respondents indicated that corruption reporting is rare; with respect to logistical barriers, they reported that there are no means to report. Related to both assertions, 30% of pilot respondents said that they felt reporting corruption was useless, and 50% said reporting was dangerous.

In the present experiment, we tested a norms intervention, which aimed to address individuals’ perception that corruption reporting is rare, and a nudge intervention, which aimed to minimize the perceived logistical barriers to corruption reporting. We first worked with a Nigerian anticorruption group to establish a toll-free text messaging platform. We then launched two campaigns that raised awareness of the platform and that attempted to (i) shift perceptions of the norms of corruption reporting and (ii) reduce barriers to reporting using a nudge. We tracked corruption reports texted into the platform from each community for 160 days. We also fielded a survey in each community several days after both campaigns were implemented.

The first campaign was a 2-hour Nigerian (“Nollywood”) feature film produced for this project with well-known actors. It was filmed in the Niger Delta region where the study took place. The film’s dramatic storyline incorporated corruption as part of the characters’ everyday lives. The film campaign was rolled out in a between-community design. The design entailed that half of the study communities received a treatment version of the film and half received a placebo version. The packaging of the two versions was identical except that different phone numbers for texting reports were included on the covers in small letters. The treatment version included scenes in which the actors reported corruption using our texting platform as part of the overall corruption storyline (Fig. 1, A and B). These scenes showing role models reporting corruption were designed to shift viewers’ perceptions of corruption-reporting norms. Specifically, the role models’ behavior was used to increase audience perception that other Nigerians report and approve of corruption reporting. The role models in the film were fictional but also high-status actors filmed in the audience’s local Nigerian context. A placebo version of the film cut these corruption-reporting scenes, which were not central to the film’s resolution.

Fig. 1 Social norms campaign film scene and results. (A and B) Scenes from the treatment version of the Nollywood film, depicting characters texting in corruption reports. (Photo credit: Graeme Blair, University of California, Los Angeles; Rebecca Littman, Massachusetts Institute of Technology; Elizabeth Levy Paluck, Princeton University). (C and D) Time series plotting the average daily number of text messages that engaged with the campaign and that reported a concrete corruption event, respectively, from communities where we delivered the treatment versus placebo version of the film. Locally estimated scatterplot smoothing (LOESS) lines are overlaid.

Both the treatment and placebo versions of the film advertised the corruption-reporting platform at the beginning, middle, and end of the film with a banner across the screen and on the film packaging. Thus, all film viewers had the information needed to use the corruption-reporting platform. Because we randomized which version of the film was distributed in each community, we are able to estimate the causal effect of the role models in the treatment film compared with the placebo on corruption-reporting and perceived norms.

The second campaign was a mass text message sent to all customers of Nigeria’s largest mobile phone provider in each study community, after the community received either the treatment or placebo film. The mass text was sent to people in each community on a randomly assigned date a few weeks following the film distribution using a stepped wedge design. By virtue of this randomization, we are able to estimate the causal effect of the message by comparing response rates before and after the randomly assigned date of the nudge. The message alerted individuals to the corruption-reporting platform and explained the ease of reporting (Fig. 2A). In this way, the message was designed to reduce barriers to reporting by clearly explaining the reporting campaign, allowing recipients to simply hit “reply” to report, and emphasizing that correspondence with the corruption platform was free (an unusual feature; see Methods and Materials for more details on each campaign).

Fig. 2 Nudge campaign text and results. (A) Mass text nudge sent to phones. (Photo credit: Graeme Blair, University of California, Los Angeles; Rebecca Littman, Massachusetts Institute of Technology; Elizabeth Levy Paluck, Princeton University). (B and C) Time series plotting the average daily number of text messages that engaged with the campaign and that reported a concrete corruption event, respectively, from communities that received the text on a randomly assigned day following the film distribution. LOESS lines are overlaid.

Thus, the film campaign and the text message campaign both attempted to encourage individuals to adopt corruption reporting via text, either by promoting the perception that corruption reporting was becoming more normative, i.e., widespread and accepted (via role models in the film), or by reducing barriers to reporting (via a text-based reminder with simple and encouraging instructions). Neither campaign promised investigative action in response to a report, and any person who inquired via text message was told that reports would be used by a Nigerian activist organization. Both campaigns made salient the issue of corruption, although daily life already highlights this issue to the majority of Nigerians. Our film intervention controls for salience of the corruption-reporting platform: We compare corruption reports and norms among people who watched either the treatment or the placebo film, both of which provided information about the corruption-reporting campaign hotline. Within this film experiment, we assess whether corruption reporting is further boosted by a nudge from a text message sent on a randomly assigned day to both communities that received the treatment film or the placebo film.