Wechsler Classification of Intelligence

Wechsler Classification of Intelligence

• Gurprit Ganda
• Jul 29, 2024
• 3 min read

Intelligence is a multifaceted construct that has intrigued psychologists for decades. Among the various frameworks developed to measure and understand intelligence, the Wechsler classification stands out as one of the most comprehensive and widely used systems. Named after its creator, David Wechsler, this classification has significantly influenced both clinical practice and research in psychology (Kaufman & Lichtenberger, 2006).

The History of Wechsler Classification of Intelligence

David Wechsler was an American psychologist who sought to create a more nuanced understanding of human intelligence. Dissatisfied with existing measures like the Stanford-Binet test, he introduced the first version of his own test in 1939: the Wechsler-Bellevue Intelligence Scale (Wechsler, 1939). Over time, this evolved into several versions tailored for different age groups:

• Wechsler Adult Intelligence Scale (WAIS)

  : For adults aged 16-90.

Wechsler Adult Intelligence Scale (WAIS)

: For adults aged 16-90.

• Wechsler Intelligence Scale for Children (WISC)

  : For children aged 6-16.

Wechsler Intelligence Scale for Children (WISC)

: For children aged 6-16.

• Wechsler Preschool and Primary Scale of Intelligence (WPPSI): For children aged 2 years 6 months to 7 years 7 months.

Wechsler Preschool and Primary Scale of Intelligence (WPPSI): For children aged 2 years 6 months to 7 years 7 months.

These scales have undergone multiple revisions to improve their reliability and validity, making them some of the most trusted tools in psychological assessment (Coalson & Raiford, 2008).

Components of the Wechsler Scales

The Wechsler scales are designed to provide a comprehensive assessment by measuring different facets of intelligence. Each scale comprises several subtests that fall under four primary indices (Wechsler, 2008):

• Verbal Comprehension Index (VCI)

Verbal Comprehension Index (VCI)

• Perceptual Reasoning Index (PRI)

Perceptual Reasoning Index (PRI)

• Working Memory Index (WMI)

Working Memory Index (WMI)

• Processing Speed Index (PSI)

Processing Speed Index (PSI)

Example: A 10-year-old child, Kenta, undergoes a WISC-V assessment. Her scores reveal high performance in Verbal Comprehension tasks but lower scores in Processing Speed. This profile helps her teachers understand why she excels in language-based subjects but struggles with timed tests.

Interpretation of Scores

Scores from these subtests are combined to produce an overall IQ score, which falls into one of several categories according to the Wechsler classification (Wechsler, 2014):

• Very Superior (130+)

Very Superior (130+)

• Superior (120-129)

Superior (120-129)

• High Average (110-119)

High Average (110-119)

• Average (90-109)

Average (90-109)

• Low Average (80-89)

Low Average (80-89)

• Borderline (70-79)

Borderline (70-79)

• Extremely Low (