Evidence of gender bias in legal insanity evaluations: A case vignette study of clinicians, judges and students

Forensic psychiatric decision-making plays a key role in the legal process of homicide cases. Research show that women defendants have a higher likelihood of being declared legally insane and being diverted to hospital. This study attempted to explore if this gender difference is explained by biases in the forensic psychiatric assessments. Participants were 45 practicing forensic psychiatric clinicians, 46 chief judges and 80 psychology students. Participants received a written vignette describing a homicide case, with either a female or a male perpetrator. The results suggested strong gender effects on legal insanity judgements. Forensic psychiatric clinicians and psychology students assessed the case information as more indicative of legal insanity if the perpetrator was a woman than a man. Judges assessed offenders of their own gender, as they were more likely to be declared legally insane than a perpetrator of the opposite gender. Implications of and possible ways to minimize such gender biases in forensic psychiatric evaluations need to be thoroughly considered by the legal system.