Beyond the formal rules, other strong reference points can help explain why people might engage in corrupt practices. These reference points can be broadly thought of as social norms, the unwritten rules of behaviour, which are rooted in shared (as opposed to individual) attitudes and beliefs.

There are two main types of social norms. First, there are norms based on the perceived frequency of a given behaviour. This is called a descriptive norm. When it comes to bribery, descriptive norms are captured in the explanation “I pay bribes because everybody does.” The second aspect of social norms refers to the perceived acceptability of a given behaviour: whether it is considered right or wrong, a socially appropriate course of action or not. This might be captured in a statement like “Giving gifts to officials in exchange for services isn’t wrong because you are showing your gratitude for their help.” This is called an injunctive norm.

To better analyse the link between social norms and corruption, it is important to understand that there is not just one source of social norms, but several. Social norms theory highlights that a person typically belongs to multiple social networks, some considered essential to a person’s identity, others more peripheral. People may be subject to multiple normative pressures depending on whom they meet, whom they compare themselves to, and to whom they are accountable. We can already see that speaking of a single corruption norm that needs to be tackled is insufficient.

To provide an analytical lens for the complex social normative forces of corruption, we propose a framework that looks at the main sources or types of social normative pressures, distinguishing between those pressures that stem from society, namely sociability and kinship pressures, and sources of pressures that emerge vertically or horizontally within organisations.

Sociability pressures can be summed up as “I have to return the favour,” a norm stemming from a general unwritten rule that when one receives benefits from a person in authority, it is “sociable” to offer something in return. Kinship pressures relate to the notion of “family first” and respond to pressure stemming from a sense of obligation to kin. Horizontal pressures result from a sense that “my colleagues are doing it too” creating within-institution peer pressures. Vertical pressures mean “I am forced from above” relating to pressures from higher-ups.

How to map and diagnose normative pressures

Designing successful interventions requires a thorough understanding of the social forces that perpetuate the corrupt practices. This requires research to identify important reference groups for key actors, the norms that prevail within these groups, the channels for social pressures to enforce these norms, and the anticipated sanctions for deviance. In section II of the main paper we provide an overview of the available methodologies to do this, including: literature reviews, interviews, focus groups, vignettes, corruption games, surveys and social network analysis.

Anti-corruption strategies for relieving normative pressures

Realising a social norms approach to anti-corruption means developing sets of interventions that are distinct from the standard repertoire of interventions. Nevertheless, the approach is complementary: the purpose of social norms strategies is to relieve and shift social pressures so the other kinds of interventions – such as codes of conduct, salary increases, legal reform, enforcement, and civil society oversight – can be effective. Therefore, social norms strategies should always be part of a policy mix.

After recognising which normative forces exert pressure for a given corrupt practice, practitioners should tailor the intervention to that pressure. Therefore, we arrange interventions around the four principal types of pressure identified above. We present here not prescriptions but policy approaches, clarifying why each approach may address a particular pressure. These are intended as general guidelines for practitioners: the particular intervention will have to be developed according to the features of each case and the respective entry points. Please see the main paper for more details.