Social marketing aims to address social problems by changing human behaviour, either by increasing the incidence of pro-social behaviours or decreasing the incidence of anti-social behaviours. In pursuit of these goals, social marketers use an established step-by-step process for developing, implementing, and evaluating behaviour change campaigns. They aim to change specific behaviours among specific individuals within a specific setting at a specific time. Social marketing campaigns draw on and, in turn, contribute to our understanding of human behaviour because they often utilise relevant psychological theories to achieve their goals. Social marketers begin by defining the goal of their campaign, as well as the setting in which it will be applied, the individuals it will target, and the specific behaviour it will aim to change. Then, additional background research provides information about what makes behavioural change more or less likely, and this information is used to craft the framing and content of the campaign. Finally, campaigns are implemented and evaluated, using a combination of behavioural and attitudinal outcomes. More than simply providing a proof of concept indicating whether and how psychological theories can be applied to address real-world problems, social marketing also extends psychological theory by highlighting how features of the situation and population affect psychological phenomena.