Dr Holly Carter is a Research Fellow in the Behavioural Science Research Team at Public Health England, Porton Down. Her research interests include factors which affect public behaviour during mass emergencies and disasters, in particular the role of effective responder communication in improving positive outcomes during mass decontamination. Holly has completed a PhD in crowd behaviour during incidents involving mass decontamination. The focus of this research was on the mediating role of social identity processes between effective responder communication and positive behavioural and psychological outcomes during mass decontamination. Findings from Holly’s PhD, and subsequent research, have been used to inform various decontamination guidance documents and training for emergency responders in mass decontamination. Holly is interested in psychosocial aspects of mass emergencies and disasters, and in factors which affect the way in which members of the public respond to recommendations and interventions implemented by the authorities.