Online Radicalisation: A Rapid Review of the Literature

By Rosamund Mutton, James Lewis, and Sarah Marsden

This guide sets out the evidence base for ‘online radicalisation’, examining how individual use of the Internet, in conjunction with offline influences, can facilitate radicalisation processes. The UK is the main context of concern, however comparable evidence is found in studies with samples from the USA, Canada, Belgium, Germany, Austria, and Israel. Radicalisation remains a contentious concept and few studies explicitly define ‘online radicalisation’. For the purposes of this guide, ‘radicalisation’ is understood as leading to cognitive outcomes reflected in changes in beliefs and ideas, and/or behavioural outcomes which manifest in changes in behaviour. Two systematic literature reviews (Hassan et al., 2018; Carthy et al., 2020) directed initial searches for relevant research. Further literature was identified through forward and backward citation searching, and narrower key word searches conducted in Google Scholar. Literature searches were completed between June and August 2022. The guide primarily examines literature published between January 2017 and July 2022. Although the evidence base remains modest in size, the research underpinning this guide is assessed to be good quality. There is a growing body of evidence that uses qualitative and quantitative methods to examine a range of factors which are relevant to online radicalisation.

Scotland: Centre for Research and Evidence on Security Threats, 2023, 42p.