leader theory The popular opinion leader theory suggests a parallel between peer education and the marketing of commercial products. Peer educators are seen as opinion leaders—respected and admired by other members of the community. These opinion leaders espouse a certain lifestyle (such as safer sex, or not smoking, etc.)—and their peers wish to emulate them. Critical consciousness Campbell argues that what peer education ought to do is to promote the kind of critical consciousness theorised by Paulo Freire. This means that peers use the peer education process to critically discuss their circumstances, especially the social factors impacting upon their health. Becoming critically aware of these forces is the first step to tackling them. So, for instance, if local norms regarding sexuality and gender put people's health at risk, this approach argues that peers should critically discuss those norms, so that they can then collectively seek to establish new more health-enhancing norms. Social learning theory Based on the work of Bandura and colleagues, social learning theory claims that modelling is an important component of the learning process. In the most basic sense, people observe behaviour taking place and then go on to adopt similar behaviour. Participants require the opportunity to practice modelled behavior and positive reinforcement if it is to be adopted successfully. Differential association theory Based on the work of Sutherland and Cressy, differential association theory has been applied to the study of crime. Rather than the result of biological or psychological disorders, crime is a learned behaviour. This learning happens in social situations by associating with those who can teach the necessary skills and techniques needed. Through this theory it can be understood that peers can be very influential for both positive and negative behaviours. Young people can learn both good and bad habits from each other. In differential association theory the mere association with others provides a learning opportunity. If social learning theory is essentially psychological, differential association theory is essentially sociological. Role theory Sarbin argues that peer educators will adapt to the role expectations of a tutor and behave appropriately. Furthermore, through adopting a role, individuals develop a deeper understanding and commitment to it. The potential is that Peer educators can develop a stronger commitment and a greater appreciation of the relevance of the health topic. Role theory is also based on the premise that communication can be blocked by differences in culture between the teacher and