WAIS Historical Development of the Wechsler Scales

Question 1

What was the first intelligence scale David Wechsler published, in 1939?

Accepted Answer

Wechsler-Bellevue Intelligence Scale

Answer

Wechsler developed the Wechsler-Bellevue Intelligence Scale (1939) at Bellevue Hospital in New York. The WAIS followed in 1955.

Question 2

Wechsler popularized the 'deviation IQ'. How does it differ from the older ratio IQ?

Accepted Answer

It compares a person's performance with same-age peers on a scale with a set mean and SD

Answer

The ratio IQ (MA/CA × 100) does not work for adults, because mental age levels off. The deviation IQ places a person's score within the distribution for their age group, with a mean of 100 and SD of 15.

Question 3

Which WAIS edition dropped the Verbal IQ (VIQ) and Performance IQ (PIQ) in favor of four index scores and the FSIQ?

Accepted Answer

WAIS-IV (2008)

Answer

The WAIS-III reported both VIQ/PIQ and four indexes. The WAIS-IV (2008) dropped VIQ and PIQ and kept the four-index model (VCI, PRI, WMI, PSI) plus the FSIQ.

Question 4

The Flynn effect is one reason the WAIS is periodically restandardized. Roughly how much does it raise IQ scores?

Accepted Answer

About 3 points per decade

Answer

Flynn documented population IQ gains of roughly 3 points per decade. Old norms therefore become 'soft' and overestimate current IQ, which matters a great deal in high-stakes settings such as intellectual disability determinations.

Question 5

Wechsler defined intelligence as the 'aggregate or global capacity of the individual to act purposefully, to think rationally, and to deal effectively with his environment.' What does this definition stress?

Accepted Answer

A general capacity expressed through many different abilities

Answer

Wechsler saw intelligence as a global capacity that shows up through many distinct abilities. That is why his scales sample several subtest types and combine them into a composite.

(WAIS) Wechsler Adult Intelligence Scale Practice Test

(WAIS) Wechsler Adult Intelligence Scale Practice Test

WAIS Historical Development of the Wechsler Scales