FSIQ
Definition
Full-Scale IQ; derived from 10 core WAIS-IV subtests; primary score used in intellectual disability determinations and Atkins proceedings.
- Full name
- Full-Scale IQ
- Derived from
- 10 core WAIS-IV subtests
- Primary use
- Intellectual disability determinations
- Legal context
- Atkins proceedings
Common questions
Why does FSIQ carry particular weight in Atkins proceedings?+
Atkins v. Virginia bars execution of individuals with intellectual disability, and FSIQ below approximately 70 to 75, combined with adaptive functioning deficits and onset before adulthood, forms one prong of the clinical criteria courts rely on to decide eligibility, making the score a central piece of evidence.
Is a single FSIQ score treated as a precise, final figure in forensic evaluation?+
No. Clinicians report a confidence interval around the score and account for the standard error of measurement, practice effects from repeat testing, and the Flynn effect on norms over time, since a single point estimate can misrepresent true functioning if treated as exact.
Related terms
- Atkins V. Virginia
- US Supreme Court 2002 decision holding that executing intellectually disabled defendants violates the Eighth Amendment; requires DSM-standard intellectual disability determination including Flynn-corrected...
- BNSS § 367
- Provision of India's Bharatiya Nagarik Suraksha Sanhita 2023 governing court procedure when an accused person appears to be of unsound mind; cognitive...
- Dual-Deficit Requirement
- DSM-5 requirement for intellectual disability diagnosis: deficits in both measured intellectual functioning and adaptive behaviour, both present before age 18.
- Flynn Effect
- Documented approximately 3-point-per-decade rise in population mean IQ scores; requires correction when IQ scores obtained with older norms are used in legal...
- Hall V. Florida
- US Supreme Court 2014 decision requiring courts to account for IQ measurement error and the Flynn effect before enforcing rigid IQ cutoffs...
- MacCAT-CA
- MacArthur Competence Assessment Tool for Criminal Adjudication; a 22-item standardised instrument measuring Understanding, Reasoning, and Appreciation of the trial process, grounded in...
- NIMHANS Neuropsychological Battery
- Normative neuropsychological battery published by NIMHANS Bangalore with Indian-population norms; primary reference for forensic cognitive assessment in India.
- Performance Validity Test (PVT)
- Any test designed to detect inadequate effort or deliberate underperformance in cognitive assessment; TOMM is the leading example for memory; embedded PVTs...
- Vineland-3
- Vineland Adaptive Behavior Scales, Third Edition; standardised semi-structured interview measuring adaptive functioning; required for DSM-5 intellectual disability determination alongside IQ testing.
- WAIS-IV
- Wechsler Adult Intelligence Scale, Fourth Edition; 15-subtest, 4-index IQ battery; gold standard for forensic intellectual functioning assessment.
- WMS-IV
- Wechsler Memory Scale, Fourth Edition; standardised memory battery providing five Memory Index scores; core of forensic neuropsychological memory assessment.