It’s natural to think of scientists as truth seekers, people driven by an intense curiosity to understand the natural world. Yet this picture of scientists and scientific inquiry sits uncomfortably with the reality and prevalence of scientific fraud. If one wants to get at the truth about nature, why lie? Won’t that just set inquiry back, as people pursue false leads? To understand why this occurs – and what can be done about it – we need to understand the social structures scientists work within, and how some of the institutions which enable science to be such a successful endeavour all things considered, also abet and encourage fraud.