Determinations of mental retardation: the influence of standard of proof

Abstract

The effects of two standards of proof (preponderance of the evidence and clear and convincing) and quantified definitions (quantified and non-quantified definitions) on two dependant variables (mock juror determinations of intellectual disability and numerical definitions of the standards of proof) were examined. One-hundred and thirty-nine undergraduate students were asked to read a transcript and determine if the defendant in the transcript had ID. Participants were also asked to complete questionnaires designed to measure their need for cognition, right-wing authoritarianism, endorsement of negative attitudes regarding individuals with intellectual disability, and their intelligence. Analyses indicated that standard of proof and quantification significantly affected whether mock jurors believed the defendant met criteria for ID and their numerical definitions of the two standards. There were no significant moderating variables. Limitations of and implications from the study are discussed.