Recently, we are facing, worldwide, an increasing interest in applying findings of the behavioural sciences (mainly cognitive psychology and behavioural economics) to policymaking. This phenomenon has been sometimes called ‘the behavioural turn’ in policy. Behavioural approaches are drawn upon in a variety of policy fields such as health and environmental policy, consumer protection law, as well as, for instance, in policies that tackle poverty. The behavioural turn gained momentum around ten years ago after the publication of the book ‘Nudge’ by Thaler & Sunstein. Application of behavioural research to policy has polarized scholars into fierce critics and devoted enthusiasts. All participants in the debate take at face value the image of the behavioural sciences that the advocates of the behavioural policy subscribe to. This image is mistaken, however. Building upon the scholarship in the history of the behavioural sciences (especially during the Cold War period in the US), as well as on insights from the philosophy of science (especially work of Helen Longino), Malecka will show that behavioural research has been misconceived in policy settings, as well as in academic discussions accompanying the behavioural turn. She then preliminarily suggests how a more philosophically sophisticated view on the behavioural sciences could be conceptualized. She asks whether such a nuanced view on behavioural science poses a serious challenge for the behavioural turn, as it is recently understood and advocated.