This chapter summarises some of the research that supports the book's principal argument that legitimacy is central to effective policing, and that policing policy and practice need to keep a sharp focus on factors that build or destroy police legitimacy. The chapter does not set out to provide a comprehensive survey of the literature as other reviews are available. Rather, I shall try to give a flavour of the research, drawing mainly on international surveys that I and colleagues have carried out. I shall also summarise research that provides explanations for the importance that we all attach to fair treatment from those who exercise power over us.

The evidence about procedural fairness is largely quantitative, using surveys, and there is a dearth of detailed qualitative work. Surveys necessarily offer a simplified version of the complexities of the real world. To emphasise this, the chapter starts with an extract from field notes for a qualitative, observational study that illustrates the real-world dilemmas facing patrol officers who are at risk of finding themselves in hard power traps (see Box 3.1). I hope the field notes speak for themselves.

Surveys of trust, legitimacy and compliance

In aggregate, the evidence supporting the approach for which I argue is strong but not beyond question. Evidence about the best ways of making people behave well is rarely clinching because the relevant research has to grapple with human behaviour at its most complex. I offer my own assessment of the quality of the evidence at the end of this chapter, and leave it to the reader to decide what weight to attach to it. However, it scarcely needs saying that I find it persuasive.