Over at the Oxford University Press blog, a great piece highlighting research being done on the impacts and influences of networks and communities on behavior changes:
More recently, attention is being paid to the importance of interpersonal influences through the study of social networks. Smoking cessation rates of individuals increase as more contacts in their social network quit smoking, and individuals gain weight as more contacts in their social network gain weight. Another example of social influence is an after-school program for teenagers that may not change attitudes but may reduce the opportunity to engage in risky behaviors. Organizational support for behavior change can be in the form of higher taxes on tobacco or alcohol, building recreational centers to enhance physical activity, cleaning up the environment (in one study, neighborhood deterioration was a better predictor of sexually transmitted disease than low education attainment), and using or regulating message delivery by the media.
Easy to see the continued importance of a close study of incentives, which may or may not be economic in nature. For example, social and psychological incentives matter. For more, check out the entire article on the OUPblog.