Factors affecting juror decision-making in infanticide and insanity cases

LITERATURE REVIEW Infanticide, the murder of a child aged between 24 hours and 12 months, dates back to Ancient Greece, where it was primarily used for population control. It still occurs in modem society, although illegally, and is often associated with the mother experiencing a postpartum illness (Laporte et al., 2003). In Tasmania, if a woman murders her child under the age of 12 months, she may plead guilty to the legislated crime of Infanticide. This offers her a lesser charge of manslaughter, resulting in a variety of sentencing options including psychiatric treatment. In contrast, as American law does not incorporate the Infanticide provision, the defendant must prove that she is Not Guilty by Reason of Insanity. This incorporates a legal, rather than psychiatric, conception of insanity, or mental illness (Yannoulidis, 2003). This has led to critics arguing that the Infanticide provision is redundant and stereotypes women as being susceptible to mental disorders. Further, it is argued that the insanity defence needs to be updated to incorporate a psychological definition of insanity as generally understood by the public (Osborne, 1997). Whilst it is accepted that juror characteristics interplay to affect their decision-making and verdicts rendered, there are areas where little information exists as to the effects of specific attributes (for example, gender of the juror). Skeem, Louden and Evans (2004) argued that the Insanity Defence Attitudes Scale-Revised (IDA-R) can help researchers predict jurors' verdicts regarding insanity cases depending on how negatively they score on the scale. However, in order to develop a greater understanding of what attributes affect juror's verdicts, more fine-grained research is required, including exploring infanticide cases and leading to an updated insanity defence. EMPIRICAL STUDY This study examined the effect of juror characteristics when rendering verdicts on an infanticide case, as well as investigating the efficaciousness of the infanticide provision and insanity defence. 437 participants aged between 17 to 62 years were asked to complete two questionnaires (Insanity Defence Attitudes Revised scale and the Marlowe-Crowne Social Desirability Scale), read a case vignette and render individual verdicts regarding the criminal responsibility of the defendant in question. The results of this study indicated that a defendant's psychological history (either a single episode or recurring) had little influence over a mock jurors' decision, however a woman experiencing postpartum depression (in contrast to postpartum psychosis) was more likely to be convicted of murder. Further, the study attempted to examine whether a revised insanity defence proposed by Yannoulidis (2003) would be more effective and easier to understand than the traditional insanity defence. The study offers support for the revised insanity defence, with this verdict being rendered more often than a guilty of murder verdict, compared to the traditional insanity defence. Whilst female mock jurors' reported higher levels of sympathy towards the victim and defendant compared to males, this did not make a significant impact on their decision making. The current study offers preliminary findings as to juror characteristics that interplay on the juror decision making process in infanticide cases.