WAIS-IV
Definition
Wechsler Adult Intelligence Scale, Fourth Edition; 15-subtest, 4-index IQ battery; gold standard for forensic intellectual functioning assessment.
- Full name
- Wechsler Adult Intelligence Scale, Fourth Edition
- Subtests
- 15
- Index scores
- 4 (Verbal Comprehension, Perceptual Reasoning, Working Memory, Processing Speed)
- Role
- Standard instrument for forensic intellectual functioning assessment
Common questions
Why does WAIS-IV matter specifically in forensic evaluations?+
Its Full Scale IQ score is central to determinations such as intellectual disability claims in capital sentencing, competency to stand trial, and mitigation arguments, so evaluators are expected to use a current, normed version and to interpret index-level scatter rather than relying on the single composite alone.
What can undermine the reliability of a WAIS-IV score in court?+
Practice effects from repeated testing, malingering or symptom exaggeration, cultural or linguistic mismatch with the normative sample, and administration errors can all distort the result, which is why cross-checking with validity measures and collateral records is standard practice.
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...
- FSIQ
- Full-Scale IQ; derived from 10 core WAIS-IV subtests; primary score used in intellectual disability determinations and Atkins proceedings.
- 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.
- WMS-IV
- Wechsler Memory Scale, Fourth Edition; standardised memory battery providing five Memory Index scores; core of forensic neuropsychological memory assessment.