ORIGINAL PAPER The impact of psychopathy on violence among the household population of Great Britain Jeremy Coid • Min Yang Received: 20 July 2009 / Accepted: 10 March 2010 Ó Springer-Verlag 2010 Abstract Background The public health impact of psychopathy on violence has not previously been measured in the general population. Methods Psychopathy was measured using the Psychop- athy Checklist:Screening Version (PCL:SV) in adults 16– 74 years (n = 638) in households in England, Scotland and Wales in a two-phase survey which included self-reported measures of violence. Results Participants with PCL:SV scores 11 or above demonstrated a prevalence of 2.1% (95% CI 1.2, 3.8) but accounted for 18.7% of violent incidents, a population- attributable risk of 16.6%, and demonstrated an exponen- tial rise in reported violent incidents. Psychopathic traits correlated with victim injury, multiple victim subtypes and locations. Conclusions Psychopathy makes a substantial impact on violence among the general population despite a low prevalence. Explanations of this association include inter- personal difficulties due to psychopathic traits, fearless- ness, thrill seeking, and antisocial lifestyle, but not impulsivity independent of antisocial lifestyle. Keywords Psychopathy Á Violence Á Public health Á Population survey Introduction Psychopathy is characterised by major affective deficit associated with multiple social and behavioural problems [1] and has strong links with aggression. Experimental studies suggest mechanisms to explain these associations, including thrill seeking, sadism, fearlessness, and the symptoms of psychopathy, specifically lack of remorse, poor anger control, impulsivity, and violence as part of an antisocial lifestyle [2]. However, associations between psychopathy and violence at the population level remain unclear. Self-reported violent behaviour is demonstrated to have a similar, high base-rate in both the UK and USA associated with demographic factors of male gender, younger age, lower socioeconomic status, and psychiatric morbidity, predominantly substance misuse and antisocial personality disorder [3–8]. Psychopathy is a rare condition with a prevalence of less than 1% in the British household population [9]. This suggests that its contribution to the overall level of violence in a population should be small, although this has not been previously quantified. Psycho- pathic traits demonstrate a quasi-continuous distribution in the general population [9] and most persons have no psy- chopathic traits. But those with traits could be at increased risk of violent behaviour. Representative population sam- ples could demonstrate different associations with violence from those previously reported among selected, experi- mental samples of violent offenders. The aim of this study was to examine the distribution of psychopathic traits and self-reported violent behaviour, elucidate their correlates, and estimate the contribution of psychopathy to violence among the population of Great Britain in a two-phase survey of a representative sample of adults in households aged 16–74 years, conducted in 2000. We used the PCL:SV to examine the relationship between J. Coid (&) Queen Mary University of London, William Harvey House, 61 Bartholomew Close, London EC1A 7BE, UK e-mail: j.w.coid@qmul.ac.uk M. Yang School of Community Health Sciences, University of Nottingham, University of Nottingham Innovation Park, 9 Triumph Road, Nottingham NG7 2TU, UK e-mail: min.yang@nottingham.ac.uk 123 Soc Psychiat Epidemiol DOI 10.1007/s00127-010-0212-4