Deadly Statistics: IQ Scores and Capital Punishment in Hall v. Florida

• Activity Number: 510
• Type: Invited
• Date/Time: Wednesday, August 12, 2015 : 10:30 AM to 12:20 PM
• Sponsor: Scientific and Public Affairs Advisory Committee
• Author(s): David Kaye*
• Companies: Penn State
• Keywords: psychometrics ; law ; IQ ; capital punishment ; confidence intervals ; burden of persuasion

Abstract

Over ten years ago, the U.S. Supreme Court held that executing an intellectually disabled individual is unconstitutional. In response, Florida and certain other states adopted a rule that no one with and IQ score above 70 could be considered intellectually disabled. In striking down this rule in a 2014 case, the Court split 5 to 4 over the legal implications of measurement error and the statistics used to express a "margin of error." This talk evaluates the justices' understanding of the statistical concepts and and the relationship between standard errors in true scores and the legal burden of persuasion.