Juror Decision-Making and Diminished Responsibility: Diagnosis has little impact, but Stigma may matter (a partial replication of Baker et al (2022)).

Little is known about the interaction between mental health information, juror stigma towards mental health conditions, and juror decision-making. The present study sought to partially replicate previous research (Baker et al, 2022) which had investigated how a personality disorder diagnosis may influence juror decision-making concerning the partial defence of Diminished Responsibility. The present study recruited an online general population sample where participants viewed a set of and experimentally manipulated video vignettes describing a homicide offence. These were identical except for the clinical description used (‘psychopathy’, ‘personality disorder’ or ‘complex mental health condition’). The results suggested that whilst the diagnostic manipulation made little difference to Diminished Responsibility decisions, stigmatic attitudes towards offenders with mental health conditions, as well as a greater tendency to see the defendant’s actions as more within their personal control, were associated with a lower likelihood of supporting the partial defence of Diminished Responsibility.