"Atkins v. Virginia" (2002) dramatically raised the stakes for mental retardation in capital punishment cases, but neither defined this condition nor imposed uniform standards for its assessment. The basic premise that mean IQ scores shift over time enjoys wide recognition, but its application--including the appropriateness of characterizing it in terms of an allegedly predictable "Flynn effect"--is frequently debated in the course of death penalty litigation. The scientifically and ethically sound approach to this issue is to report IQ scores as obtained and be prepared to address those factors that might affect their reliability. Altering the IQ scores themselves is insufficiently supported by professional literature, legal authority, or prevailing standards of practice.