An Examination of the Relationship between Juror Attitudes, Psychological Constructs, and Verdict Decisions within Rape Trials

For many, the English criminal justice system is considered to be among the best in the world. An important feature of the system’s success is thought to be the jury trial whereby in the most serious of cases, use of ordinary citizens to determine guilt is thought to make for fairer verdict outcomes. Yet despite being a more democratic process, questionable verdicts and low conviction rates for crimes such as rape have led many to question how impartial lay jurors are likely to be and to what extent preconceived biases may in fact be influencing verdict decisions. The overarching aim of the current thesis was thereby to examine the relationship between personal characteristics and juror decisions. Specifically, the role of psychopathic personality traits, rape attitudes, and juror demographics upon individual decision formation were examined. Another aim was to develop and validate a self-report measure of individual juror decision making, directly integrating theoretical features of the dominant model of jury decision making into an empirically testable scale. Tested separately between two independent samples within Experiment one, an opportunity sample of 324 university students comprised within 27 separate jury panels observed a videotaped mock rape trial before making individual and collective decisions. Within Experiment two, a systematic randomly selected sample of 100 community participants comprised within nine separate jury panels observed a live rape trial re-enactment before making individual and collective decisions. All participants completed demographic, attitudinal, and psychological self-report measures before the onset of the trial including; the Psychopathic Personality Trait Scale (PPTS), Acceptance of Modern Myths about Sexual Aggression (AMMSA), and the Juror Decision Scale (JDS). Results displayed evidence of a discernible relationship between juror’s psycho-social make-up and the verdict decisions made during trial. Latent profile analyses revealed psychopathic personality traits were significantly associated with verdict preferences in the community sample and regression analyses displayed elevated rape attitude scores were consistent predictors of Not Guilty verdict decisions across both samples, pre and post-deliberation. Confirmatory factorial techniques displayed a bifactor model with three meaningful factors while controlling for the general factor was the best representation of the JDS data, with the three subscales evidencing differential predictive validity with external variables. Finally, path analyses revealed the structure of the relationship between all variables and verdict decisions, providing further evidence for the role of juror characteristics. These findings strongly support the assertion that within rape trials, juror decisions are directly related with the attitudes and psychological constructs jurors bring to trial. Evidence that a juror’s psycho-social make-up affects their interpretation of the evidence and ultimately predisposes them towards particular verdict decisions, gives rise to the possibility of needing to screen biased individuals out the jury trial process in the future. Whether change occurs or not to such historical English jury procedures, what can no longer be simply dismissed, is the role of individual juror bias upon trial outcomes within rape.