Mostly the same test, measured against new people
Is the drop with age real?
On this version, the 66-year-olds came in 6.4 IQ points below the 16-year-olds when all eleven subtests were averaged. A separate estimate put the generational gain across that fifty-year span at 14.1 points. On that account, the age gap disappears.1
Kaufman came out elsewhere. He lined up people from the same birth cohorts who had been tested 25 years apart and still saw decline, especially on nonverbal work. Adjusting for education and rising scores left that result standing.3
Same age, four norm samples
Four editions, each showing people aged 70 to 74. The scores stay on the young-adult scale, not an age-corrected one. Choose a measure to see whether later cohorts arrive 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]Kaufman, A. S., McLean, J. E., & Reynolds, C. R. (1988). Sex, race, residence, region, and education differences on the 11 WAIS-R subtests. Journal of Clinical Psychology, 44(2), 231-248.doi.org
- [8]Ryan, J. J., Paolo, A. M., & Brungardt, T. M. (1990). Standardization of the Wechsler Adult Intelligence Scale-Revised for persons 75 years and older. Psychological Assessment, 2(4), 404-411.doi.org
- [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.