James is an academic psychologist at King’s College London, where he is a Professor of Psychology & Emerging Health Risks. His main research interest is in understanding how people perceive health risks and what implications these perceptions have for how people behave and for their physical and mental well-being. He has published over 180 peer-reviewed academic papers on these and related topics.

James’s work covers two overlapping areas. The first assesses the importance of perceptions relating to suddenly occurring mass exposure to a potentially hazardous substance. Much of this work is conducted under the auspices of the NIHR Health Protection Research Unit in Emergency Preparedness and Response, which he is the Director for. The second area involves understanding how psychological and social factors can determine whether or not a person will develop symptoms following exposure to a potentially hazardous substance. James has previously published papers on why people attribute physical symptoms or seek health care following apparent exposure to mobile phone signals, wifi, police radio systems, common chemicals, wind turbines, swine flu, chemical terrorism and outbreaks of plague, among other things. As a result of his research, he has been invited to work with UK, EU and World Health Organisation bodies investigating the potential effects of newly identified health risks, and is an honorary non-medical consultant with the Emergency Response Department at the UK Health Security Agency 

James has also provided legal expert witness statements as part of several high profile group litigation cases (in England and internationally) in which the claimants attributed symptoms to controversial medical implants or industrial exposures, was a participant in the UK's Scientific Advisory Group for Emergencies (SAGE) during the COVID-19 pandemic, and was asked to set up and co-chair SAGE's behavioural science subgroup.