Mostly the same test, measured against new people
Is the drop with age real?
In WAIS-R data, 66-year-olds scored about 6.4 IQ points below 16-year-olds, averaged across all 11 subtests. The generational rise in scores (the Flynn effect) over the same 50-year gap was estimated at 14.1 points, enough to account for the whole difference.1
Kaufman reached a different conclusion. Comparing each WAIS-R age group with the same birth cohort tested 25 years earlier, he found real declines, steeper on nonverbal than verbal subtests, and not explained by education or rising scores.3
Same age, four norm samples
Scores for 70-to-74-year-olds from four editions, not corrected for age, so they're on the young-adult scale. Pick a measure to see whether each generation of older adults scored higher.
Figures from Miller (2009), who derived age-uncorrected means for the 70–74 groups.3 Sample sizes are given for 1955, 1981 and 1997 only.
What the 1997 edition changed
References
- [1]Agbayani, K. A. Patterns of age-related IQ changes from the WAIS to WAIS-III after adjustment for the Flynn effect. University of Houston (PDF).uh-ir.tdl.org
- [2]Age differences and educational attainment across the life span on three generations of Wechsler adult scales (2016). Journal of Psychoeducational Assessment, 34(5), 421–441 (PDF).uva.theopenscholar.com
- [3]Miller, L. S. et al. (2009). Changes in intellectual functioning associated with normal aging. Montana Legislature archive (PDF).archive.legmt.gov
- [4]Master's thesis on the WISC-R and WAIS-R. Western Michigan University ScholarWorks (PDF).scholarworks.wmich.edu
- [5]The Wechsler Adult Intelligence Scale (WAIS). SlideShare presentation.slideshare.net
- [6]Wechsler Adult Intelligence Scale: an overview. ScienceDirect Topics (Medicine and Dentistry).sciencedirect.com
- [7]WAIS: comprehensive summary of the Wechsler Adult Intelligence Scale. Studocu.studocu.com
- [8]Wechsler Adult Intelligence Scale. Grokipedia (2026).grokipedia.com
- [9]Wechsler Adult Intelligence Scale (WAIS). IQ Test Prep.iqtestprep.com
Related historical tests
The 1955 test the WAIS-R re-normed about 25 years later. Comparing the two samples is how researchers first measured how much adult scores had shifted.
Revised seven years earlier. With both tests covering age 16, examiners could choose either for 16-year-olds.
A co-normed ability and achievement battery from four years earlier. It later went to ages 90 and over, beyond the WAIS-R's upper limit of 74.
Cattell's fluid-intelligence test. The WAIS-R pattern of steeper decline on nonverbal subtests fits the idea that fluid abilities fall faster with age.
Wechsler's 1939 scale is where the verbal/performance split that the WAIS-R still used began.
Wechsler's preschool scale. With the WPPSI, WISC-R and WAIS-R, the family covered ages from 4 to 74 by 1981.