The article intends to present the debate on behaviour modification in the regulation studies literature, at a time of renewed interest among regulators for new ideas and strategies. As the financial crisis has led to the most public critique yet of the rational choice view of individuals that has informed regulation in the last few decades, other ideas that value realism more than simplicity and parsimony deserve some attention. Some of these--proposed by behavioural economics--have already raised considerable interest from regulators, especially in the UK and the USA, and have begun to impact various types of regulation. This article puts these various elements in perspective and as such provides tools to appraise and engage with past and future attempts to regulate social groups in health care and elsewhere. (Contains 1 note.)