Social issues affect all individuals in a given society. They are problems that question the moral values of individuals and are concerned with what people are willing to give up to benefit the collective. Social issues that are not addressed could have severe economic, political and social consequences. The objective of this study is to develop a model that examines why individuals comply or do not comply with pro-social behaviour. Using an online survey, which focused on pro-social behaviour in an environmental context, undergraduate students from the University of Guelph responded to questions that measured variables drawn from relevant literature. Findings suggest not all variables were applicable to the pro-environmental behaviour context. Findings also suggest variables that were thought to moderate the relationship between the independent and dependent variable might actually mediate the relationship instead. Consequently, the model was revised and tested a posteriori.